DevTools: [Responsive design] shift-drag resize widget for more precise dragging

Source/devtools/front_end/ui/ResizerWidget.js

 // Copyright 2014 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.
 
 /**
  * @constructor
  * @extends {WebInspector.Object}
  */
 WebInspector.ResizerWidget = function()
 {
     WebInspector.Object.call(this);
 
     this._isEnabled = true;
     this._isVertical = true;
     this._elements = [];
     this._installDragOnMouseDownBound = this._installDragOnMouseDown.bind(this);
 };
 
 WebInspector.ResizerWidget.Events = {
-    ResizeStart: "ResizeStart",  // Data: {{startPosition: number, currentPosition: number}}.
-    ResizeUpdate: "ResizeUpdate",  // Data: {{startPosition: number, currentPosition: number}}.
-    ResizeEnd: "ResizeEnd"  // No data.
+    ResizeStart: "ResizeStart",
+    ResizeUpdate: "ResizeUpdate",
+    ResizeEnd: "ResizeEnd"
 };
 
 WebInspector.ResizerWidget.prototype = {
     /**
      * @return {boolean}
      */
     isEnabled: function()
     {
         return this._isEnabled;
     },
@@ skipping 98 matching lines @@
      * @return {boolean}
      */
     _drag: function(event)
     {
         if (!this._isEnabled) {
             this._dragEnd(event);
             return true;  // Cancel drag.
         }
 
         var position = this._isVertical ? event.pageY : event.pageX;
-        this.dispatchEventToListeners(WebInspector.ResizerWidget.Events.ResizeUpdate, { startPosition: this._startPosition, currentPosition: position });
+        this.dispatchEventToListeners(WebInspector.ResizerWidget.Events.ResizeUpdate, { startPosition: this._startPosition, currentPosition: position, shiftKey: event.shiftKey });
         event.preventDefault();
         return false;  // Continue drag.
     },
 
     /**
      * @param {!MouseEvent} event
      */
     _dragEnd: function(event)
     {
         this.dispatchEventToListeners(WebInspector.ResizerWidget.Events.ResizeEnd);
         delete this._startPosition;
     },
 
     __proto__: WebInspector.Object.prototype
 };