[DevTools] Remove Common.Event.target field.

third_party/WebKit/Source/devtools/front_end/sources/JavaScriptSourceFrame.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 266 matching lines @@
           contextMenu.appendItem(addSourceMapURLLabel, addSourceMapURL.bind(null, scriptFile));
           contextMenu.appendSeparator();
         }
       }
     }
 
     return super.populateTextAreaContextMenu(contextMenu, lineNumber, columnNumber)
         .then(populateSourceMapMembers.bind(this));
   }
 
+  /**
+   * @param {!Common.Event} event
+   */
   _workingCopyChanged(event) {
     if (this._supportsEnabledBreakpointsWhileEditing() || this._scriptFileForTarget.size)
       return;
 
     if (this.uiSourceCode().isDirty())
       this._muteBreakpointsWhileEditing();
     else
       this._restoreBreakpointsAfterEditing();
   }
 
+  /**
+   * @param {!Common.Event} event
+   */
   _workingCopyCommitted(event) {
     this._scriptsPanel.updateLastModificationTime();
     if (this._supportsEnabledBreakpointsWhileEditing())
       return;
 
     if (!this._scriptFileForTarget.size)
       this._restoreBreakpointsAfterEditing();
   }
 
   _didMergeToVM() {
@@ skipping 1065 matching lines @@
   hide() {
     if (!this.bookmark)
       return;
     this.bookmark.clear();
     this.bookmark = null;
   }
 };
 
 Sources.JavaScriptSourceFrame.BreakpointDecoration.bookmarkSymbol = Symbol('bookmark');
 Sources.JavaScriptSourceFrame.BreakpointDecoration._elementSymbolForTest = Symbol('element');