Merge "Prevent redefinition of class libraries"
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-image.js b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-image.js
index b897708..1896c76 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-image.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-image.js
@@ -14,6 +14,9 @@
 (function(window, GrDiffBuilderSideBySide) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffBuilderImage) { return; }
+
   function GrDiffBuilderImage(diff, comments, prefs, outputEl, baseImage,
       revisionImage) {
     GrDiffBuilderSideBySide.call(this, diff, comments, prefs, outputEl);
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-side-by-side.js b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-side-by-side.js
index 8f1b6b6..1044b77 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-side-by-side.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-side-by-side.js
@@ -14,6 +14,9 @@
 (function(window, GrDiffBuilder) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffBuilderSideBySide) { return; }
+
   function GrDiffBuilderSideBySide(diff, comments, prefs, outputEl) {
     GrDiffBuilder.call(this, diff, comments, prefs, outputEl);
   }
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-unified.js b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-unified.js
index 2f1aac6..e69f369 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-unified.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder-unified.js
@@ -14,6 +14,9 @@
 (function(window, GrDiffBuilder) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffBuilderUnified) { return; }
+
   function GrDiffBuilderUnified(diff, comments, prefs, outputEl) {
     GrDiffBuilder.call(this, diff, comments, prefs, outputEl);
   }
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.js b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.js
index 8acf936..b96423e 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-builder/gr-diff-builder.js
@@ -14,6 +14,9 @@
 (function(window, GrDiffGroup, GrDiffLine) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffBuilder) { return; }
+
   function GrDiffBuilder(diff, comments, prefs, outputEl) {
     this._diff = diff;
     this._comments = comments;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-group.js b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-group.js
index 7c7c508..638d7f5 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-group.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-group.js
@@ -14,6 +14,9 @@
 (function(window, GrDiffLine) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffGroup) { return; }
+
   function GrDiffGroup(type, opt_lines) {
     this.type = type;
     this.lines = [];
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-line.js b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-line.js
index 4acde0c..2a5913c 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-line.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff-line.js
@@ -14,6 +14,9 @@
 (function(window) {
   'use strict';
 
+  // Prevent redefinition.
+  if (window.GrDiffLine) { return; }
+
   function GrDiffLine(type) {
     this.type = type;
     this.highlights = [];