diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
index 1aba403..a8ed5bc 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
@@ -18,9 +18,7 @@
 <link rel="import" href="../../../bower_components/polymer/polymer.html">
 <link rel="import" href="../../../behaviors/gr-patch-set-behavior/gr-patch-set-behavior.html">
 <link rel="import" href="../../../styles/shared-styles.html">
-<link rel="import" href="../../core/gr-reporting/gr-reporting.html">
 <link rel="import" href="../../shared/gr-button/gr-button.html">
-<link rel="import" href="../../shared/gr-rest-api-interface/gr-rest-api-interface.html">
 <link rel="import" href="../gr-diff-builder/gr-diff-builder.html">
 <link rel="import" href="../gr-diff-comment-thread/gr-diff-comment-thread.html">
 <link rel="import" href="../gr-diff-highlight/gr-diff-highlight.html">
@@ -270,26 +268,26 @@
         <div>[[item]]</div>
       </template>
     </div>
-    <div class$="[[_computeContainerClass(_loggedIn, viewMode, displayLine)]]"
+    <div class$="[[_computeContainerClass(loggedIn, viewMode, displayLine)]]"
         on-tap="_handleTap">
-      <gr-diff-selection diff="[[_diff]]">
+      <gr-diff-selection diff="[[diff]]">
         <gr-diff-highlight
             id="highlights"
-            logged-in="[[_loggedIn]]"
+            logged-in="[[loggedIn]]"
             comments="{{comments}}">
           <gr-diff-builder
               id="diffBuilder"
               comments="[[comments]]"
               project-name="[[projectName]]"
-              diff="[[_diff]]"
+              diff="[[diff]]"
               diff-path="[[path]]"
               change-num="[[changeNum]]"
               patch-num="[[patchRange.patchNum]]"
               view-mode="[[viewMode]]"
               line-wrapping="[[lineWrapping]]"
               is-image-diff="[[isImageDiff]]"
-              base-image="[[_baseImage]]"
-              revision-image="[[_revisionImage]]"
+              base-image="[[baseImage]]"
+              revision-image="[[revisionImage]]"
               parent-index="[[_parentIndex]]"
               create-comment-fn="[[_createThreadGroupFn]]"
               line-of-interest="[[lineOfInterest]]">
@@ -301,16 +299,16 @@
         </gr-diff-highlight>
       </gr-diff-selection>
     </div>
-    <div class$="[[_computeNewlineWarningClass(_newlineWarning, _loading)]]">
+    <div class$="[[_computeNewlineWarningClass(_newlineWarning, loading)]]">
       [[_newlineWarning]]
     </div>
-    <div id="loadingError" class$="[[_computeErrorClass(_errorMessage)]]">
-      [[_errorMessage]]
+    <div id="loadingError" class$="[[_computeErrorClass(errorMessage)]]">
+      [[errorMessage]]
     </div>
     <div id="sizeWarning" class$="[[_computeWarningClass(_showWarning)]]">
       <p>
         Prevented render because "Whole file" is enabled and this diff is very
-        large (about [[_diffLength(_diff)]] lines).
+        large (about [[_diffLength(diff)]] lines).
       </p>
       <gr-button on-tap="_handleLimitedBypass">
         Render with limited context
@@ -319,8 +317,6 @@
         Render anyway (may be slow)
       </gr-button>
     </div>
-    <gr-rest-api-interface id="restAPI"></gr-rest-api-interface>
-    <gr-reporting id="reporting" category="diff"></gr-reporting>
   </template>
   <script src="gr-diff-line.js"></script>
   <script src="gr-diff-group.js"></script>
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.js b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.js
index 881d97f..4f0a73b 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.js
@@ -21,11 +21,6 @@
   const ERR_COMMENT_ON_EDIT_BASE = 'You cannot comment on the base patch set ' +
       'of an edit.';
   const ERR_INVALID_LINE = 'Invalid line number: ';
-  const MSG_EMPTY_BLAME = 'No blame information for this diff.';
-
-  const EVENT_AGAINST_PARENT = 'diff-against-parent';
-  const EVENT_ZERO_REBASE = 'rebase-percent-zero';
-  const EVENT_NONZERO_REBASE = 'rebase-percent-nonzero';
 
   const NO_NEWLINE_BASE = 'No newline at end of base file.';
   const NO_NEWLINE_REVISION = 'No newline at end of revision file.';
@@ -64,6 +59,12 @@
      * @event diff-comments-modified
      */
 
+     /**
+      * Fired when a draft is added or edited.
+      *
+      * @event draft-interaction
+      */
+
     properties: {
       changeNum: String,
       noAutoRender: {
@@ -88,15 +89,8 @@
       },
       isImageDiff: {
         type: Boolean,
-        computed: '_computeIsImageDiff(_diff)',
-        notify: true,
       },
       commitRange: Object,
-      filesWeblinks: {
-        type: Object,
-        value() { return {}; },
-        notify: true,
-      },
       hidden: {
         type: Boolean,
         reflectToAttribute: true,
@@ -123,38 +117,33 @@
        */
       lineOfInterest: Object,
 
-      /**
-       * If the diff fails to load, show the failure message in the diff rather
-       * than bubbling the error up to the whole page. This is useful for when
-       * loading inline diffs because one diff failing need not mark the whole
-       * page with a failure.
-       */
-      showLoadFailure: Boolean,
-
-      _loading: {
+      loading: {
         type: Boolean,
         value: false,
         observer: '_loadingChanged',
       },
 
-      _loggedIn: {
+      loggedIn: {
         type: Boolean,
         value: false,
       },
-      _diff: Object,
+      diff: {
+        type: Object,
+        observer: '_diffChanged',
+      },
       _diffHeaderItems: {
         type: Array,
         value: [],
-        computed: '_computeDiffHeaderItems(_diff.*)',
+        computed: '_computeDiffHeaderItems(diff.*)',
       },
       _diffTableClass: {
         type: String,
         value: '',
       },
       /** @type {?Object} */
-      _baseImage: Object,
+      baseImage: Object,
       /** @type {?Object} */
-      _revisionImage: Object,
+      revisionImage: Object,
 
       /**
        * Whether the safety check for large diffs when whole-file is set has
@@ -172,20 +161,16 @@
       _showWarning: Boolean,
 
       /** @type {?string} */
-      _errorMessage: {
+      errorMessage: {
         type: String,
         value: null,
       },
 
       /** @type {?Object} */
-      _blame: {
+      blame: {
         type: Object,
         value: null,
-      },
-      isBlameLoaded: {
-        type: Boolean,
-        notify: true,
-        computed: '_computeIsBlameLoaded(_blame)',
+        observer: '_blameChanged',
       },
 
       _parentIndex: {
@@ -195,7 +180,7 @@
 
       _newlineWarning: {
         type: String,
-        computed: '_computeNewlineWarning(_diff)',
+        computed: '_computeNewlineWarning(diff)',
       },
 
       /**
@@ -220,63 +205,6 @@
       'create-comment': '_handleCreateComment',
     },
 
-    attached() {
-      this._getLoggedIn().then(loggedIn => {
-        this._loggedIn = loggedIn;
-      });
-    },
-
-    ready() {
-      if (this._canRender()) {
-        this.reload();
-      }
-    },
-
-    /** @return {!Promise} */
-    reload() {
-      this._loading = true;
-      this._errorMessage = null;
-
-      const diffRequest = this._getDiff()
-          .then(diff => {
-            this._reportDiff(diff);
-            return diff;
-          })
-          .catch(e => {
-            this._handleGetDiffError(e);
-            return null;
-          });
-
-      const assetRequest = diffRequest.then(diff => {
-        // If the diff is null, then it's failed to load.
-        if (!diff) { return null; }
-
-        return this._loadDiffAssets(diff);
-      });
-
-      return Promise.all([diffRequest, assetRequest])
-          .then(results => {
-            const diff = results[0];
-            if (!diff) {
-              return Promise.resolve();
-            }
-            this.filesWeblinks = this._getFilesWeblinks(diff);
-            this._diff = diff;
-            return new Promise(resolve => {
-              const callback = () => {
-                resolve();
-                this.removeEventListener('render', callback);
-              };
-              this.addEventListener('render', callback);
-              this._renderDiffTable();
-            });
-          })
-          .catch(err => {
-            console.warn('Error encountered loading diff:', err);
-          })
-          .then(() => { this._loading = false; });
-    },
-
     /** Cancel any remaining diff builder rendering work. */
     cancel() {
       this.$.diffBuilder.cancel();
@@ -300,37 +228,13 @@
       this.toggleClass('no-left');
     },
 
-    /**
-     * Load and display blame information for the base of the diff.
-     * @return {Promise} A promise that resolves when blame finishes rendering.
-     */
-    loadBlame() {
-      return this.$.restAPI.getBlame(this.changeNum, this.patchRange.patchNum,
-          this.path, true)
-          .then(blame => {
-            if (!blame.length) {
-              this.fire('show-alert', {message: MSG_EMPTY_BLAME});
-              return Promise.reject(MSG_EMPTY_BLAME);
-            }
-
-            this._blame = blame;
-
-            this.$.diffBuilder.setBlame(blame);
-            this.classList.add('showBlame');
-          });
-    },
-
-    _computeIsBlameLoaded(blame) {
-      return !!blame;
-    },
-
-    /**
-     * Unload blame information for the diff.
-     */
-    clearBlame() {
-      this._blame = null;
-      this.$.diffBuilder.setBlame(null);
-      this.classList.remove('showBlame');
+    _blameChanged(newValue) {
+      this.$.diffBuilder.setBlame(newValue);
+      if (newValue) {
+        this.classList.add('showBlame');
+      } else {
+        this.classList.remove('showBlame');
+      }
     },
 
     _handleCommentSaveOrDiscard() {
@@ -338,12 +242,6 @@
           {bubbles: true}));
     },
 
-    /** @return {boolean}} */
-    _canRender() {
-      return !!this.changeNum && !!this.patchRange && !!this.path &&
-          !this.noAutoRender;
-    },
-
     /** @return {!Array<!HTMLElement>} */
     getThreadEls() {
       let threads = [];
@@ -432,7 +330,7 @@
 
     /** @return {boolean} */
     _isValidElForComment(el) {
-      if (!this._loggedIn) {
+      if (!this.loggedIn) {
         this.fire('show-auth-required');
         return false;
       }
@@ -461,7 +359,7 @@
      * @param {!Object=} opt_range
      */
     _createComment(lineEl, opt_lineNum, opt_side, opt_range) {
-      this.$.reporting.recordDraftInteraction();
+      this.dispatchEvent(new CustomEvent('draft-interaction', {bubbles: true}));
       const contentText = this.$.diffBuilder.getContentByLineEl(lineEl);
       const contentEl = contentText.parentElement;
       const side = opt_side ||
@@ -681,7 +579,7 @@
     _loadingChanged(newValue) {
       if (newValue) {
         this.cancel();
-        this.clearBlame();
+        this._blame = null;
         this._safetyBypass = null;
         this._showWarning = false;
         this.clearDiffContent();
@@ -695,7 +593,7 @@
     _prefsChanged(prefs) {
       if (!prefs) { return; }
 
-      this.clearBlame();
+      this._blame = null;
 
       const stylesToUpdate = {};
 
@@ -716,7 +614,13 @@
 
       this.updateStyles(stylesToUpdate);
 
-      if (this._diff && this.comments && !this.noRenderOnPrefsChange) {
+      if (this.diff && this.comments && !this.noRenderOnPrefsChange) {
+        this._renderDiffTable();
+      }
+    },
+
+    _diffChanged(newValue) {
+      if (newValue) {
         this._renderDiffTable();
       }
     },
@@ -727,7 +631,7 @@
         return;
       }
       if (this.prefs.context === -1 &&
-          this._diffLength(this._diff) >= LARGE_DIFF_THRESHOLD_LINES &&
+          this._diffLength(this.diff) >= LARGE_DIFF_THRESHOLD_LINES &&
           this._safetyBypass === null) {
         this._showWarning = true;
         this.dispatchEvent(new CustomEvent('render', {bubbles: true}));
@@ -752,138 +656,6 @@
       this.$.diffTable.innerHTML = null;
     },
 
-    _handleGetDiffError(response) {
-      // Loading the diff may respond with 409 if the file is too large. In this
-      // case, use a toast error..
-      if (response.status === 409) {
-        this.fire('server-error', {response});
-        return;
-      }
-
-      if (this.showLoadFailure) {
-        this._errorMessage = [
-          'Encountered error when loading the diff:',
-          response.status,
-          response.statusText,
-        ].join(' ');
-        return;
-      }
-
-      this.fire('page-error', {response});
-    },
-
-    /** @return {!Promise<!Object>} */
-    _getDiff() {
-      // Wrap the diff request in a new promise so that the error handler
-      // rejects the promise, allowing the error to be handled in the .catch.
-      return new Promise((resolve, reject) => {
-        this.$.restAPI.getDiff(
-            this.changeNum,
-            this.patchRange.basePatchNum,
-            this.patchRange.patchNum,
-            this.path,
-            reject)
-            .then(resolve);
-      });
-    },
-
-    _getFilesWeblinks(diff) {
-      if (!this.commitRange) { return {}; }
-      return {
-        meta_a: Gerrit.Nav.getFileWebLinks(
-            this.projectName, this.commitRange.baseCommit, this.path,
-            {weblinks: diff && diff.meta_a && diff.meta_a.web_links}),
-        meta_b: Gerrit.Nav.getFileWebLinks(
-            this.projectName, this.commitRange.commit, this.path,
-            {weblinks: diff && diff.meta_b && diff.meta_b.web_links}),
-      };
-    },
-
-    /**
-     * Report info about the diff response.
-     */
-    _reportDiff(diff) {
-      if (!diff || !diff.content) { return; }
-
-      // Count the delta lines stemming from normal deltas, and from
-      // due_to_rebase deltas.
-      let nonRebaseDelta = 0;
-      let rebaseDelta = 0;
-      diff.content.forEach(chunk => {
-        if (chunk.ab) { return; }
-        const deltaSize = Math.max(
-            chunk.a ? chunk.a.length : 0, chunk.b ? chunk.b.length : 0);
-        if (chunk.due_to_rebase) {
-          rebaseDelta += deltaSize;
-        } else {
-          nonRebaseDelta += deltaSize;
-        }
-      });
-
-      // Find the percent of the delta from due_to_rebase chunks rounded to two
-      // digits. Diffs with no delta are considered 0%.
-      const totalDelta = rebaseDelta + nonRebaseDelta;
-      const percentRebaseDelta = !totalDelta ? 0 :
-          Math.round(100 * rebaseDelta / totalDelta);
-
-      // Report the due_to_rebase percentage in the "diff" category when
-      // applicable.
-      if (this.patchRange.basePatchNum === 'PARENT') {
-        this.$.reporting.reportInteraction(EVENT_AGAINST_PARENT);
-      } else if (percentRebaseDelta === 0) {
-        this.$.reporting.reportInteraction(EVENT_ZERO_REBASE);
-      } else {
-        this.$.reporting.reportInteraction(EVENT_NONZERO_REBASE,
-            percentRebaseDelta);
-      }
-    },
-
-    /** @return {!Promise} */
-    _getLoggedIn() {
-      return this.$.restAPI.getLoggedIn();
-    },
-
-    /**
-     * @param {Object} diff
-     * @return {boolean}
-     */
-    _computeIsImageDiff(diff) {
-      if (!diff) { return false; }
-
-      const isA = diff.meta_a &&
-          diff.meta_a.content_type.startsWith('image/');
-      const isB = diff.meta_b &&
-          diff.meta_b.content_type.startsWith('image/');
-
-      return !!(diff.binary && (isA || isB));
-    },
-
-    /**
-     * @param {Object} diff
-     * @return {!Promise}
-     */
-    _loadDiffAssets(diff) {
-      if (this._computeIsImageDiff(diff)) {
-        return this._getImages(diff).then(images => {
-          this._baseImage = images.baseImage;
-          this._revisionImage = images.revisionImage;
-        });
-      } else {
-        this._baseImage = null;
-        this._revisionImage = null;
-        return Promise.resolve();
-      }
-    },
-
-    /**
-     * @param {Object} diff
-     * @return {!Promise}
-     */
-    _getImages(diff) {
-      return this.$.restAPI.getImagesForDiff(this.changeNum, diff,
-          this.patchRange);
-    },
-
     _projectConfigChanged(projectConfig) {
       const threadEls = this.getThreadEls();
       for (let i = 0; i < threadEls.length; i++) {
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_test.html b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_test.html
index dda3ca6..0274fae 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_test.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff_test.html
@@ -48,18 +48,8 @@
       sandbox.restore();
     });
 
-    test('reload cancels before network resolves', () => {
-      element = fixture('basic');
-      const cancelStub = sandbox.stub(element, 'cancel');
-
-      // Stub the network calls into requests that never resolve.
-      sandbox.stub(element, '_getDiff', () => new Promise(() => {}));
-
-      element.reload();
-      assert.isTrue(cancelStub.called);
-    });
-
     test('cancel', () => {
+      element = fixture('basic');
       const cancelStub = sandbox.stub(element.$.diffBuilder, 'cancel');
       element.cancel();
       assert.isTrue(cancelStub.calledOnce);
@@ -208,41 +198,6 @@
             element.$$('.diffContainer').classList.contains('displayLine'));
       });
 
-      test('loads files weblinks', () => {
-        const weblinksStub = sandbox.stub(Gerrit.Nav, '_generateWeblinks')
-            .returns({name: 'stubb', url: '#s'});
-        sandbox.stub(element.$.restAPI, 'getDiff').returns(Promise.resolve({
-          content: [],
-        }));
-        element.projectName = 'test-project';
-        element.path = 'test-path';
-        element.commitRange = {baseCommit: 'test-base', commit: 'test-commit'};
-        element.patchRange = {};
-        return element.reload().then(() => {
-          assert.isTrue(weblinksStub.calledTwice);
-          assert.isTrue(weblinksStub.firstCall.calledWith({
-            commit: 'test-base',
-            file: 'test-path',
-            options: {
-              weblinks: undefined,
-            },
-            repo: 'test-project',
-            type: Gerrit.Nav.WeblinkType.FILE}));
-          assert.isTrue(weblinksStub.secondCall.calledWith({
-            commit: 'test-commit',
-            file: 'test-path',
-            options: {
-              weblinks: undefined,
-            },
-            repo: 'test-project',
-            type: Gerrit.Nav.WeblinkType.FILE}));
-          assert.deepEqual(element.filesWeblinks, {
-            meta_a: [{name: 'stubb', url: '#s'}],
-            meta_b: [{name: 'stubb', url: '#s'}],
-          });
-        });
-      });
-
       test('remove comment', () => {
         element.comments = {
           meta: {
@@ -408,66 +363,29 @@
             'wsAAAAAAAAAAAAA/////w==',
             type: 'image/bmp',
           };
-          const mockCommit = {
-            commit: '9a1a1d10baece5efbba10bc4ccf808a67a50ac0a',
-            parents: [{
-              commit: '7338aa9adfe57909f1fdaf88975cdea467d3382f',
-              subject: 'Added a carrot',
-            }],
-            author: {
-              name: 'Wyatt Allen',
-              email: 'wyatta@google.com',
-              date: '2016-05-23 21:44:51.000000000',
-              tz: -420,
-            },
-            committer: {
-              name: 'Wyatt Allen',
-              email: 'wyatta@google.com',
-              date: '2016-05-25 00:25:41.000000000',
-              tz: -420,
-            },
-            subject: 'Updated the carrot',
-            message: 'Updated the carrot\n\nChange-Id: Iabcd123\n',
-          };
-          const mockComments = {baseComments: [], comments: []};
-
-          sandbox.stub(element.$.restAPI, 'getCommitInfo')
-              .returns(Promise.resolve(mockCommit));
-          sandbox.stub(element.$.restAPI,
-              'getB64FileContents',
-              (changeId, patchNum, path, opt_parentIndex) => {
-                return Promise.resolve(opt_parentIndex === 1 ? mockFile1 :
-                    mockFile2);
-              });
-          sandbox.stub(element.$.restAPI, '_getDiffComments')
-              .returns(Promise.resolve(mockComments));
-          sandbox.stub(element.$.restAPI, 'getDiffDrafts')
-              .returns(Promise.resolve(mockComments));
 
           element.patchRange = {basePatchNum: 'PARENT', patchNum: 1};
           element.comments = {left: [], right: []};
+          element.isImageDiff = true;
+          element.prefs = {
+            auto_hide_diff_table_header: true,
+            context: 10,
+            cursor_blink_rate: 0,
+            font_size: 12,
+            ignore_whitespace: 'IGNORE_NONE',
+            intraline_difference: true,
+            line_length: 100,
+            line_wrapping: false,
+            show_line_endings: true,
+            show_tabs: true,
+            show_whitespace_errors: true,
+            syntax_highlighting: true,
+            tab_size: 8,
+            theme: 'DEFAULT',
+          };
         });
 
         test('renders image diffs with same file name', done => {
-          const mockDiff = {
-            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
-            meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
-              lines: 560},
-            intraline_status: 'OK',
-            change_type: 'MODIFIED',
-            diff_header: [
-              'diff --git a/carrot.jpg b/carrot.jpg',
-              'index 2adc47d..f9c2f2c 100644',
-              '--- a/carrot.jpg',
-              '+++ b/carrot.jpg',
-              'Binary files differ',
-            ],
-            content: [{skip: 66}],
-            binary: true,
-          };
-          sandbox.stub(element.$.restAPI, 'getDiff')
-              .returns(Promise.resolve(mockDiff));
-
           const rendered = () => {
             // Recognizes that it should be an image diff.
             assert.isTrue(element.isImageDiff);
@@ -522,10 +440,24 @@
 
           element.addEventListener('render', rendered);
 
-          element.$.restAPI.getDiffPreferences().then(prefs => {
-            element.prefs = prefs;
-            element.reload();
-          });
+          element.baseImage = mockFile1;
+          element.revisionImage = mockFile2;
+          element.diff = {
+            meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
+            meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
+              lines: 560},
+            intraline_status: 'OK',
+            change_type: 'MODIFIED',
+            diff_header: [
+              'diff --git a/carrot.jpg b/carrot.jpg',
+              'index 2adc47d..f9c2f2c 100644',
+              '--- a/carrot.jpg',
+              '+++ b/carrot.jpg',
+              'Binary files differ',
+            ],
+            content: [{skip: 66}],
+            binary: true,
+          };
         });
 
         test('renders image diffs with a different file name', done => {
@@ -545,8 +477,6 @@
             content: [{skip: 66}],
             binary: true,
           };
-          sandbox.stub(element.$.restAPI, 'getDiff')
-              .returns(Promise.resolve(mockDiff));
 
           const rendered = () => {
             // Recognizes that it should be an image diff.
@@ -604,10 +534,11 @@
 
           element.addEventListener('render', rendered);
 
-          element.$.restAPI.getDiffPreferences().then(prefs => {
-            element.prefs = prefs;
-            element.reload();
-          });
+          element.baseImage = mockFile1;
+          element.baseImage._name = mockDiff.meta_a.name;
+          element.revisionImage = mockFile2;
+          element.revisionImage._name = mockDiff.meta_b.name;
+          element.diff = mockDiff;
         });
 
         test('renders added image', done => {
@@ -626,8 +557,6 @@
             content: [{skip: 66}],
             binary: true,
           };
-          sandbox.stub(element.$.restAPI, 'getDiff')
-              .returns(Promise.resolve(mockDiff));
 
           element.addEventListener('render', () => {
             // Recognizes that it should be an image diff.
@@ -643,10 +572,8 @@
             done();
           });
 
-          element.$.restAPI.getDiffPreferences().then(prefs => {
-            element.prefs = prefs;
-            element.reload();
-          });
+          element.revisionImage = mockFile2;
+          element.diff = mockDiff;
         });
 
         test('renders removed image', done => {
@@ -665,8 +592,6 @@
             content: [{skip: 66}],
             binary: true,
           };
-          sandbox.stub(element.$.restAPI, 'getDiff')
-              .returns(Promise.resolve(mockDiff));
 
           element.addEventListener('render', () => {
             // Recognizes that it should be an image diff.
@@ -682,10 +607,8 @@
             done();
           });
 
-          element.$.restAPI.getDiffPreferences().then(prefs => {
-            element.prefs = prefs;
-            element.reload();
-          });
+          element.baseImage = mockFile1;
+          element.diff = mockDiff;
         });
 
         test('does not render disallowed image type', done => {
@@ -706,9 +629,6 @@
           };
           mockFile1.type = 'image/jpeg-evil';
 
-          sandbox.stub(element.$.restAPI, 'getDiff')
-              .returns(Promise.resolve(mockDiff));
-
           element.addEventListener('render', () => {
             // Recognizes that it should be an image diff.
             assert.isTrue(element.isImageDiff);
@@ -719,10 +639,8 @@
             done();
           });
 
-          element.$.restAPI.getDiffPreferences().then(prefs => {
-            element.prefs = prefs;
-            element.reload();
-          });
+          element.baseImage = mockFile1;
+          element.diff = mockDiff;
         });
       });
 
@@ -769,67 +687,10 @@
         content.click();
       });
 
-      test('_getDiff handles null diff responses', done => {
-        stub('gr-rest-api-interface', {
-          getDiff() { return Promise.resolve(null); },
-        });
-        element.changeNum = 123;
-        element.patchRange = {basePatchNum: 1, patchNum: 2};
-        element.path = 'file.txt';
-        element._getDiff().then(done);
-      });
-
-      test('reload resolves on error', () => {
-        const onErrStub = sandbox.stub(element, '_handleGetDiffError');
-        const error = {ok: false, status: 500};
-        sandbox.stub(element.$.restAPI, 'getDiff',
-            (changeNum, basePatchNum, patchNum, path, onErr) => {
-              onErr(error);
-            });
-        return element.reload().then(() => {
-          assert.isTrue(onErrStub.calledOnce);
-        });
-      });
-
-      suite('_handleGetDiffError', () => {
-        let serverErrorStub;
-        let pageErrorStub;
-
-        setup(() => {
-          serverErrorStub = sinon.stub();
-          element.addEventListener('server-error', serverErrorStub);
-          pageErrorStub = sinon.stub();
-          element.addEventListener('page-error', pageErrorStub);
-        });
-
-        test('page error on HTTP-409', () => {
-          element._handleGetDiffError({status: 409});
-          assert.isTrue(serverErrorStub.calledOnce);
-          assert.isFalse(pageErrorStub.called);
-          assert.isNotOk(element._errorMessage);
-        });
-
-        test('server error on non-HTTP-409', () => {
-          element._handleGetDiffError({status: 500});
-          assert.isFalse(serverErrorStub.called);
-          assert.isTrue(pageErrorStub.calledOnce);
-          assert.isNotOk(element._errorMessage);
-        });
-
-        test('error message if showLoadFailure', () => {
-          element.showLoadFailure = true;
-          element._handleGetDiffError({status: 500, statusText: 'Failure!'});
-          assert.isFalse(serverErrorStub.called);
-          assert.isFalse(pageErrorStub.called);
-          assert.equal(element._errorMessage,
-              'Encountered error when loading the diff: 500 Failure!');
-        });
-      });
-
       suite('getCursorStops', () => {
         const setupDiff = function() {
           const mock = document.createElement('mock-diff-response');
-          element._diff = mock.diffResponse;
+          element.diff = mock.diffResponse;
           element.comments = {
             left: [],
             right: [],
@@ -878,15 +739,8 @@
     suite('logged in', () => {
       let fakeLineEl;
       setup(() => {
-        const getLoggedInPromise = Promise.resolve(true);
-        stub('gr-rest-api-interface', {
-          getLoggedIn() { return getLoggedInPromise; },
-          getPreferences() {
-            return Promise.resolve({time_format: 'HHMM_12'});
-          },
-          getAccountCapabilities() { return Promise.resolve(); },
-        });
         element = fixture('basic');
+        element.loggedIn = true;
         element.patchRange = {};
 
         fakeLineEl = {
@@ -895,15 +749,11 @@
             contains: sandbox.stub().returns(true),
           },
         };
-        return getLoggedInPromise;
       });
 
       test('addDraftAtLine', () => {
         sandbox.stub(element, '_selectLine');
         sandbox.stub(element, '_createComment');
-        const loggedInErrorSpy = sandbox.spy();
-        element.addEventListener('show-auth-required', loggedInErrorSpy);
-        assert.isFalse(loggedInErrorSpy.called);
         element.addDraftAtLine(fakeLineEl);
         assert.isTrue(element._createComment
             .calledWithExactly(fakeLineEl, 42));
@@ -913,12 +763,9 @@
         element.patchRange.basePatchNum = element.EDIT_NAME;
         sandbox.stub(element, '_selectLine');
         sandbox.stub(element, '_createComment');
-        const loggedInErrorSpy = sandbox.spy();
         const alertSpy = sandbox.spy();
-        element.addEventListener('show-auth-required', loggedInErrorSpy);
         element.addEventListener('show-alert', alertSpy);
         element.addDraftAtLine(fakeLineEl);
-        assert.isFalse(loggedInErrorSpy.called);
         assert.isTrue(alertSpy.called);
         assert.isFalse(element._createComment.called);
       });
@@ -928,19 +775,16 @@
         element.patchRange.basePatchNum = element.PARENT_NAME;
         sandbox.stub(element, '_selectLine');
         sandbox.stub(element, '_createComment');
-        const loggedInErrorSpy = sandbox.spy();
         const alertSpy = sandbox.spy();
-        element.addEventListener('show-auth-required', loggedInErrorSpy);
         element.addEventListener('show-alert', alertSpy);
         element.addDraftAtLine(fakeLineEl);
-        assert.isFalse(loggedInErrorSpy.called);
         assert.isTrue(alertSpy.called);
         assert.isFalse(element._createComment.called);
       });
 
       suite('change in preferences', () => {
         setup(() => {
-          element._diff = {
+          element.diff = {
             meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
             meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
               lines: 560},
@@ -1074,7 +918,8 @@
 
     suite('diff header', () => {
       setup(() => {
-        element._diff = {
+        element = fixture('basic');
+        element.diff = {
           meta_a: {name: 'carrot.jpg', content_type: 'image/jpeg', lines: 66},
           meta_b: {name: 'carrot.jpg', content_type: 'image/jpeg',
             lines: 560},
@@ -1087,15 +932,15 @@
 
       test('hidden', () => {
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
+        element.push('diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', 'index 2adc47d..f9c2f2c 100644');
+        element.push('diff.diff_header', 'index 2adc47d..f9c2f2c 100644');
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', '--- a/test.jpg');
+        element.push('diff.diff_header', '--- a/test.jpg');
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', '+++ b/test.jpg');
+        element.push('diff.diff_header', '+++ b/test.jpg');
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', 'test');
+        element.push('diff.diff_header', 'test');
         assert.equal(element._diffHeaderItems.length, 1);
         flushAsynchronousOperations();
 
@@ -1103,13 +948,13 @@
       });
 
       test('binary files', () => {
-        element._diff.binary = true;
+        element.diff.binary = true;
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
+        element.push('diff.diff_header', 'diff --git a/test.jpg b/test.jpg');
         assert.equal(element._diffHeaderItems.length, 0);
-        element.push('_diff.diff_header', 'test');
+        element.push('diff.diff_header', 'test');
         assert.equal(element._diffHeaderItems.length, 1);
-        element.push('_diff.diff_header', 'Binary files differ');
+        element.push('diff.diff_header', 'Binary files differ');
         assert.equal(element._diffHeaderItems.length, 1);
       });
     });
@@ -1126,7 +971,7 @@
                   new CustomEvent('render', {bubbles: true}));
             });
         const mock = document.createElement('mock-diff-response');
-        element._diff = mock.diffResponse;
+        element.diff = mock.diffResponse;
         element.comments = {left: [], right: []};
         element.noRenderOnPrefsChange = true;
       });
@@ -1171,144 +1016,19 @@
         element = fixture('basic');
       });
 
-      test('clearBlame', () => {
-        element._blame = [];
+      test('unsetting', () => {
+        element.blame = [];
         const setBlameSpy = sandbox.spy(element.$.diffBuilder, 'setBlame');
         element.classList.add('showBlame');
-        element.clearBlame();
-        assert.isNull(element._blame);
+        element.blame = null;
         assert.isTrue(setBlameSpy.calledWithExactly(null));
         assert.isFalse(element.classList.contains('showBlame'));
       });
 
-      test('loadBlame', () => {
+      test('setting', () => {
         const mockBlame = [{id: 'commit id', ranges: [{start: 1, end: 2}]}];
-        const showAlertStub = sinon.stub();
-        element.addEventListener('show-alert', showAlertStub);
-        const getBlameStub = sandbox.stub(element.$.restAPI, 'getBlame')
-            .returns(Promise.resolve(mockBlame));
-        element.changeNum = 42;
-        element.patchRange = {patchNum: 5, basePatchNum: 4};
-        element.path = 'foo/bar.baz';
-        return element.loadBlame().then(() => {
-          assert.isTrue(getBlameStub.calledWithExactly(
-              42, 5, 'foo/bar.baz', true));
-          assert.isFalse(showAlertStub.called);
-          assert.equal(element._blame, mockBlame);
-          assert.isTrue(element.classList.contains('showBlame'));
-        });
-      });
-
-      test('loadBlame empty', () => {
-        const mockBlame = [];
-        const showAlertStub = sinon.stub();
-        element.addEventListener('show-alert', showAlertStub);
-        sandbox.stub(element.$.restAPI, 'getBlame')
-            .returns(Promise.resolve(mockBlame));
-        element.changeNum = 42;
-        element.patchRange = {patchNum: 5, basePatchNum: 4};
-        element.path = 'foo/bar.baz';
-        return element.loadBlame()
-            .then(() => {
-              assert.isTrue(false, 'Promise should not resolve');
-            })
-            .catch(() => {
-              assert.isTrue(showAlertStub.calledOnce);
-              assert.isNull(element._blame);
-              assert.isFalse(element.classList.contains('showBlame'));
-            });
-      });
-    });
-
-    suite('_reportDiff', () => {
-      let reportStub;
-
-      setup(() => {
-        element = fixture('basic');
-        element.patchRange = {basePatchNum: 1};
-        reportStub = sandbox.stub(element.$.reporting, 'reportInteraction');
-      });
-
-      test('null and content-less', () => {
-        element._reportDiff(null);
-        assert.isFalse(reportStub.called);
-
-        element._reportDiff({});
-        assert.isFalse(reportStub.called);
-      });
-
-      test('diff w/ no delta', () => {
-        const diff = {
-          content: [
-            {ab: ['foo', 'bar']},
-            {ab: ['baz', 'foo']},
-          ],
-        };
-        element._reportDiff(diff);
-        assert.isTrue(reportStub.calledOnce);
-        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-zero');
-        assert.isUndefined(reportStub.lastCall.args[1]);
-      });
-
-      test('diff w/ no rebase delta', () => {
-        const diff = {
-          content: [
-            {ab: ['foo', 'bar']},
-            {a: ['baz', 'foo']},
-            {ab: ['foo', 'bar']},
-            {a: ['baz', 'foo'], b: ['bar', 'baz']},
-            {ab: ['foo', 'bar']},
-            {b: ['baz', 'foo']},
-            {ab: ['foo', 'bar']},
-          ],
-        };
-        element._reportDiff(diff);
-        assert.isTrue(reportStub.calledOnce);
-        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-zero');
-        assert.isUndefined(reportStub.lastCall.args[1]);
-      });
-
-      test('diff w/ some rebase delta', () => {
-        const diff = {
-          content: [
-            {ab: ['foo', 'bar']},
-            {a: ['baz', 'foo'], due_to_rebase: true},
-            {ab: ['foo', 'bar']},
-            {a: ['baz', 'foo'], b: ['bar', 'baz']},
-            {ab: ['foo', 'bar']},
-            {b: ['baz', 'foo'], due_to_rebase: true},
-            {ab: ['foo', 'bar']},
-            {a: ['baz', 'foo']},
-          ],
-        };
-        element._reportDiff(diff);
-        assert.isTrue(reportStub.calledOnce);
-        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-nonzero');
-        assert.strictEqual(reportStub.lastCall.args[1], 50);
-      });
-
-      test('diff w/ all rebase delta', () => {
-        const diff = {content: [{
-          a: ['foo', 'bar'],
-          b: ['baz', 'foo'],
-          due_to_rebase: true,
-        }]};
-        element._reportDiff(diff);
-        assert.isTrue(reportStub.calledOnce);
-        assert.equal(reportStub.lastCall.args[0], 'rebase-percent-nonzero');
-        assert.strictEqual(reportStub.lastCall.args[1], 100);
-      });
-
-      test('diff against parent event', () => {
-        element.patchRange.basePatchNum = 'PARENT';
-        const diff = {content: [{
-          a: ['foo', 'bar'],
-          b: ['baz', 'foo'],
-        }]};
-        element._reportDiff(diff);
-        assert.isTrue(reportStub.calledOnce);
-        assert.equal(reportStub.lastCall.args[0], 'diff-against-parent');
-        assert.isUndefined(reportStub.lastCall.args[1]);
+        element.blame = mockBlame;
+        assert.isTrue(element.classList.contains('showBlame'));
       });
     });