DevTools: Only show gutter diff for Network UISourceCodes

third_party/WebKit/Source/devtools/front_end/source_frame/SourceCodeDiff.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 /**
  * @unrestricted
  */
 SourceFrame.SourceCodeDiff = class {
   /**
    * @param {!WorkspaceDiff.WorkspaceDiff} workspaceDiff
-   * @param {!Workspace.UISourceCode} uiSourceCode
    * @param {!TextEditor.CodeMirrorTextEditor} textEditor
    */
-  constructor(workspaceDiff, uiSourceCode, textEditor) {
+  constructor(workspaceDiff, textEditor) {
     this._textEditor = textEditor;
     this._decorations = [];
     this._textEditor.installGutter(SourceFrame.SourceCodeDiff.DiffGutterType, true);
-    this._uiSourceCode = uiSourceCode;
+    this._uiSourceCode = null;
     this._workspaceDiff = workspaceDiff;
     /** @type {!Array<!TextEditor.TextEditorPositionHandle>}*/
     this._animatedLines = [];
 
-    this._workspaceDiff.subscribeToDiffChange(this._uiSourceCode, this._update, this);
     this._update();
   }
 
+  /**
+   * @param {?Workspace.UISourceCode} uiSourceCode
+   */
+  setUISourceCode(uiSourceCode) {
+    if (uiSourceCode === this._uiSourceCode)
+      return;
+    if (this._uiSourceCode)
+      this._workspaceDiff.unsubscribeFromDiffChange(this._uiSourceCode, this._update, this);
+    if (uiSourceCode)
+      this._workspaceDiff.subscribeToDiffChange(uiSourceCode, this._update, this);
+    this._uiSourceCode = uiSourceCode;
+    this._update();
+  }
+
   /**
    * @param {?string} oldContent
    * @param {?string} newContent
    */
   highlightModifiedLines(oldContent, newContent) {
     if (typeof oldContent !== 'string' || typeof newContent !== 'string')
       return;
 
     var diff = this._computeDiff(Diff.Diff.lineDiff(oldContent.split('\n'), newContent.split('\n')));
     var changedLines = [];
@@ skipping 112 matching lines @@
         from -= 1;
       }
       result.push({type: type, from: from, to: to});
       isInsideBlock = false;
       hasAdded = false;
       hasRemoved = false;
     }
   }
 
   _update() {
-    this._workspaceDiff.requestDiff(this._uiSourceCode).then(this._innerUpdate.bind(this));
+    if (this._uiSourceCode)
+      this._workspaceDiff.requestDiff(this._uiSourceCode).then(this._innerUpdate.bind(this));
+    else
+      this._innerUpdate(null);
   }
 
   /**
    * @param {?Diff.Diff.DiffArray} lineDiff
    */
   _innerUpdate(lineDiff) {
-    if (!lineDiff)
+    if (!lineDiff) {
+      this._updateDecorations(this._decorations, []);
+      this._decorations = [];
       return;
+    }
 
     /** @type {!Map<number, !SourceFrame.SourceCodeDiff.GutterDecoration>} */
     var oldDecorations = new Map();
     for (var i = 0; i < this._decorations.length; ++i) {
       var decoration = this._decorations[i];
       var lineNumber = decoration.lineNumber();
       if (lineNumber === -1)
         continue;
       oldDecorations.set(lineNumber, decoration);
     }
@@ skipping 17 matching lines @@
     this._decorationsSetForTest(newDecorations);
   }
 
   /**
    * @param {!Map<number, !{lineNumber: number, type: !SourceFrame.SourceCodeDiff.GutterDecorationType}>} decorations
    */
   _decorationsSetForTest(decorations) {
   }
 
   dispose() {
-    WorkspaceDiff.workspaceDiff().unsubscribeFromDiffChange(this._uiSourceCode, this._update, this);
+    if (this._uiSourceCode)
+      WorkspaceDiff.workspaceDiff().unsubscribeFromDiffChange(this._uiSourceCode, this._update, this);
   }
 };
 
 /** @type {string} */
 SourceFrame.SourceCodeDiff.DiffGutterType = 'CodeMirror-gutter-diff';
 
 /** @enum {symbol} */
 SourceFrame.SourceCodeDiff.GutterDecorationType = {
   Insert: Symbol('Insert'),
   Delete: Symbol('Delete'),
@@ skipping 43 matching lines @@
   }
 
   remove() {
     var location = this._position.resolve();
     if (!location)
       return;
     this._textEditor.setGutterDecoration(location.lineNumber, SourceFrame.SourceCodeDiff.DiffGutterType, null);
     this._textEditor.toggleLineClass(location.lineNumber, this._className, false);
   }
 };