diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils.ts
index d309556..0b688a6 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils.ts
@@ -188,6 +188,45 @@
   right: {[key: string]: boolean};
 }
 
+/**
+ * "Context" is the number of lines that we are showing around diff chunks and
+ * commented lines. This typically comes from a user preference and is set to
+ * something like 3 or 10.
+ *
+ * `FULL_CONTEXT` means that the user wants to see the entire file. We could
+ * also call this "infinite context".
+ */
+export const FULL_CONTEXT = -1;
+
+export enum FullContext {
+  /** User has opted into showing the full context. */
+  YES = 'YES',
+  /** User has opted into showing only limited context. */
+  NO = 'NO',
+  /**
+   * User has not decided yet. Will see a warning message with two options then,
+   * if the file is too large.
+   */
+  UNDECIDED = 'UNDECIDED',
+}
+
+export function computeContext(
+  prefsContext: number | undefined,
+  showFullContext: FullContext,
+  defaultContext: number
+) {
+  if (showFullContext === FullContext.YES) {
+    return FULL_CONTEXT;
+  }
+  if (
+    prefsContext &&
+    !(showFullContext === FullContext.NO && prefsContext === FULL_CONTEXT)
+  ) {
+    return prefsContext;
+  }
+  return defaultContext;
+}
+
 export function computeKeyLocations(
   lineOfInterest: DisplayLine | undefined,
   comments: GrDiffCommentThread[]
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
index 7e6e7fc..28c6c08 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-utils_test.ts
@@ -15,6 +15,9 @@
   toCommentThreadModel,
   compareComments,
   GrDiffThreadElement,
+  computeContext,
+  FULL_CONTEXT,
+  FullContext,
 } from './gr-diff-utils';
 import {FILE, LOST, Side} from '../../../api/diff';
 
@@ -184,6 +187,26 @@
     assert.isUndefined(getRange(threadEl));
   });
 
+  suite('computeContext', () => {
+    test('computeContext 1', () => {
+      assert.equal(computeContext(1, FullContext.YES, 2), FULL_CONTEXT);
+      assert.equal(computeContext(1, FullContext.NO, 2), 1);
+      assert.equal(computeContext(1, FullContext.UNDECIDED, 2), 1);
+    });
+
+    test('computeContext FULL_CONTEXT', () => {
+      assert.equal(
+        computeContext(FULL_CONTEXT, FullContext.YES, 2),
+        FULL_CONTEXT
+      );
+      assert.equal(computeContext(FULL_CONTEXT, FullContext.NO, 2), 2);
+      assert.equal(
+        computeContext(FULL_CONTEXT, FullContext.UNDECIDED, 2),
+        FULL_CONTEXT
+      );
+    });
+  });
+
   suite('key locations', () => {
     test('lineOfInterest is a key location', () => {
       const lineOfInterest = {lineNum: 789, side: Side.LEFT};
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff.ts
index 1f212b0..54d578a 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff.ts
@@ -28,6 +28,7 @@
   compareComments,
   toCommentThreadModel,
   KeyLocations,
+  FullContext,
 } from '../gr-diff/gr-diff-utils';
 import {BlameInfo, CommentRange, ImageInfo} from '../../../types/common';
 import {DiffInfo, DiffPreferencesInfo} from '../../../types/diff';
@@ -40,11 +41,7 @@
   CommentRangeLayer,
   GrRangedCommentLayer,
 } from '../gr-ranged-comment-layer/gr-ranged-comment-layer';
-import {
-  createDefaultDiffPrefs,
-  DiffViewMode,
-  Side,
-} from '../../../constants/constants';
+import {DiffViewMode, Side} from '../../../constants/constants';
 import {
   GrDiffProcessor,
   ProcessingOptions,
@@ -236,17 +233,6 @@
   @property({type: Boolean})
   override isContentEditable = isSafari();
 
-  /**
-   * Whether the safety check for large diffs when whole-file is set has
-   * been bypassed. If the value is null, then the safety has not been
-   * bypassed. If the value is a number, then that number represents the
-   * context preference to use when rendering the bypassed diff.
-   *
-   * Private but used in tests.
-   */
-  @state()
-  safetyBypass: number | null = null;
-
   // Private but used in tests.
   @state()
   showWarning?: boolean;
@@ -288,7 +274,7 @@
   // Private but used in tests.
   highlights = new GrDiffHighlight();
 
-  private diffModel = new DiffModel(undefined);
+  private diffModel = new DiffModel();
 
   // visible for testing
   builder?: GrDiffBuilder;
@@ -312,6 +298,7 @@
 
   private rangeLayer?: GrRangedCommentLayer;
 
+  // TODO: Remove. Let the model instantiate the processor.
   // visible for testing
   processor?: GrDiffProcessor;
 
@@ -322,8 +309,12 @@
    */
   private groups: GrDiffGroup[] = [];
 
+  // TODO: Can be removed when GrDiffProcessor is not instantiated anymore.
   private keyLocations: KeyLocations = {left: {}, right: {}};
 
+  // TODO: Can be removed when GrDiffProcessor is not instantiated anymore.
+  private context = 3;
+
   static override get styles() {
     return [
       iconStyles,
@@ -342,6 +333,11 @@
       () => this.diffModel.keyLocations$,
       keyLocations => (this.keyLocations = keyLocations)
     );
+    subscribe(
+      this,
+      () => this.diffModel.context$,
+      context => (this.context = context)
+    );
     this.addEventListener(
       'create-range-comment',
       (e: CustomEvent<CreateRangeCommentEventDetail>) =>
@@ -384,13 +380,16 @@
       changedProperties.has('prefs') ||
       changedProperties.has('lineOfInterest')
     ) {
-      this.diffModel.updateState({
-        diff: this.diff,
-        path: this.path,
-        renderPrefs: this.renderPrefs,
-        diffPrefs: this.prefs,
-        lineOfInterest: this.lineOfInterest,
-      });
+      if (this.diff && this.prefs) {
+        this.diffModel.updateState({
+          diff: this.diff,
+          path: this.path,
+          renderPrefs: this.renderPrefs ?? {},
+          diffPrefs: this.prefs,
+          lineOfInterest: this.lineOfInterest,
+          isImageDiff: this.isImageDiff,
+        });
+      }
     }
     if (
       changedProperties.has('path') ||
@@ -763,7 +762,7 @@
   private cleanup() {
     this.cancel();
     this.blame = null;
-    this.safetyBypass = null;
+    this.diffModel.updateState({showFullContext: FullContext.UNDECIDED});
     this.showWarning = false;
     this.clearDiffContent();
   }
@@ -911,10 +910,10 @@
       return;
     }
     if (
-      this.getBypassPrefs().context === -1 &&
+      this.prefs.context === FULL_CONTEXT &&
+      this.diffModel.getState().showFullContext === FullContext.UNDECIDED &&
       this.diffLength &&
-      this.diffLength >= LARGE_DIFF_THRESHOLD_LINES &&
-      this.safetyBypass === null
+      this.diffLength >= LARGE_DIFF_THRESHOLD_LINES
     ) {
       this.showWarning = true;
       fire(this, 'render', {});
@@ -1048,18 +1047,6 @@
     lostCell.insertBefore(div, lostCell.firstChild);
   }
 
-  /**
-   * Get the preferences object including the safety bypass context (if any).
-   */
-  // visible for testing
-  getBypassPrefs() {
-    assertIsDefined(this.prefs, 'prefs');
-    if (this.safetyBypass !== null) {
-      return {...this.prefs, context: this.safetyBypass};
-    }
-    return this.prefs;
-  }
-
   clearDiffContent() {
     this.unobserveNodes();
     if (!this.diffTable) return;
@@ -1083,28 +1070,23 @@
   }
 
   private handleFullBypass() {
-    this.safetyBypass = FULL_CONTEXT;
+    this.diffModel.updateState({showFullContext: FullContext.YES});
     this.debounceRenderDiffTable();
   }
 
   private collapseContext() {
+    this.diffModel.updateState({showFullContext: FullContext.NO});
     // Uses the default context amount if the preference is for the entire file.
-    this.safetyBypass =
-      this.prefs?.context && this.prefs.context >= 0
-        ? null
-        : createDefaultDiffPrefs().context;
     this.debounceRenderDiffTable();
   }
 
+  // TODO: Migrate callers to just update prefs.context.
   toggleAllContext() {
-    if (!this.prefs) {
-      return;
-    }
-    if (this.getBypassPrefs().context < 0) {
-      this.collapseContext();
-    } else {
-      this.handleFullBypass();
-    }
+    const current = this.diffModel.getState().showFullContext;
+    this.diffModel.updateState({
+      showFullContext:
+        current === FullContext.YES ? FullContext.NO : FullContext.YES,
+    });
   }
 
   private computeNewlineWarning(): string | undefined {
@@ -1152,7 +1134,7 @@
     this.builder.addColumns(this.diffTable, getLineNumberCellWidth(this.prefs));
 
     const options: ProcessingOptions = {
-      context: this.getBypassPrefs().context,
+      context: this.context,
       keyLocations: this.keyLocations,
       isBinary: !!(this.isImageDiff || this.diff.binary),
     };
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
index 99db4e9..5603edb 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff_test.ts
@@ -3801,89 +3801,6 @@
     });
   });
 
-  suite('safety and bypass', () => {
-    let renderStub: sinon.SinonStub;
-
-    setup(async () => {
-      renderStub = sinon.stub(element, 'legacyRender').callsFake(() => {
-        assertIsDefined(element.diffTable);
-        element.diffTable.dispatchEvent(
-          new CustomEvent('render', {bubbles: true, composed: true})
-        );
-        return Promise.resolve();
-      });
-      sinon.stub(element, 'getDiffLength').returns(10000);
-      element.diff = createDiff();
-      element.noRenderOnPrefsChange = true;
-      await element.updateComplete;
-    });
-
-    test('large render w/ context = 10', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: 10};
-      element.renderDiffTable();
-      await waitForEventOnce(element, 'render');
-
-      assert.isTrue(renderStub.called);
-      assert.isFalse(element.showWarning);
-    });
-
-    test('large render w/ whole file and bypass', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: -1};
-      element.safetyBypass = 10;
-      element.renderDiffTable();
-      await waitForEventOnce(element, 'render');
-
-      assert.isTrue(renderStub.called);
-      assert.isFalse(element.showWarning);
-    });
-
-    test('large render w/ whole file and no bypass', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: -1};
-      element.renderDiffTable();
-      await waitForEventOnce(element, 'render');
-
-      assert.isFalse(renderStub.called);
-      assert.isTrue(element.showWarning);
-    });
-
-    test('toggles expand context using bypass', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: 3};
-
-      element.toggleAllContext();
-      element.renderDiffTable();
-      await element.updateComplete;
-
-      assert.equal(element.prefs.context, 3);
-      assert.equal(element.safetyBypass, -1);
-      assert.equal(element.getBypassPrefs().context, -1);
-    });
-
-    test('toggles collapse context from bypass', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: 3};
-      element.safetyBypass = -1;
-
-      element.toggleAllContext();
-      element.renderDiffTable();
-      await element.updateComplete;
-
-      assert.equal(element.prefs.context, 3);
-      assert.isNull(element.safetyBypass);
-      assert.equal(element.getBypassPrefs().context, 3);
-    });
-
-    test('toggles collapse context from pref using default', async () => {
-      element.prefs = {...MINIMAL_PREFS, context: -1};
-
-      element.toggleAllContext();
-      element.renderDiffTable();
-      await element.updateComplete;
-
-      assert.equal(element.prefs.context, -1);
-      assert.equal(element.safetyBypass, 10);
-      assert.equal(element.getBypassPrefs().context, 10);
-    });
-  });
-
   suite('blame', () => {
     test('unsetting', async () => {
       element.blame = [];