[DevTools] Make resource tree model optional

third_party/WebKit/Source/devtools/front_end/console/ConsoleContextSelector.js

 // Copyright 2015 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
  * @implements {WebInspector.TargetManager.Observer}
  * @param {!Element} selectElement
  */
 WebInspector.ConsoleContextSelector = function(selectElement)
@@ skipping 16 matching lines @@
 WebInspector.ConsoleContextSelector.prototype = {
     /**
      * @param {!WebInspector.ExecutionContext} executionContext
      * @return {string}
      */
     _titleFor: function(executionContext)
     {
         var result;
         if (executionContext.isDefault) {
             if (executionContext.frameId) {
-                var frame = executionContext.target().resourceTreeModel.frameForId(executionContext.frameId);
+                var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(executionContext.target());

[pfeldman, 2016/07/07 17:44:14]

What we want here is a friendly executionContext name that should have been set
on the executionContext itself (executionContext.name). So it seems like we need
to fix it elsewhere.

The rule of thumb is that if this code should work in Node, it should not
mention resourceTreeModel. And if it mentions it, it is not nullable.

[eostroukhov-old, 2016/07/13 23:30:59]

Not sure if such a fix is in scope for this refactoring...

+                var frame = resourceTreeModel && resourceTreeModel.frameForId(executionContext.frameId);
                 result =  frame ? frame.displayName() : executionContext.label();
             } else {
                 result = executionContext.target().decorateLabel(executionContext.label());
             }
         } else {
             result = "\u00a0\u00a0\u00a0\u00a0" + (executionContext.label() || executionContext.origin);
         }
 
         var maxLength = 50;
         return result.trimMiddle(maxLength);
@@ skipping 125 matching lines @@
     /**
      * @return {?Element}
      */
     _selectedOption: function()
     {
         if (this._selectElement.selectedIndex >= 0)
             return this._selectElement[this._selectElement.selectedIndex];
         return null;
     }
 }