[DevTools] Make resource tree model optional

third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js

Index: third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
diff --git a/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js b/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
index a90496ec4d8e2447767fb0d3c2d0ae419ff2ce5a..417ab4df44ecf9c7250f97ddcffeebf223e15920 100644
--- a/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
+++ b/third_party/WebKit/Source/devtools/front_end/screencast/ScreencastView.js
@@ -97,8 +97,11 @@ WebInspector.ScreencastView.prototype = {
         this._shortcuts = /** !Object.<number, function(Event=):boolean> */ ({});
         this._shortcuts[WebInspector.KeyboardShortcut.makeKey("l", WebInspector.KeyboardShortcut.Modifiers.Ctrl)] = this._focusNavigationBar.bind(this);
 
-        this._target.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ScreencastFrame, this._screencastFrame, this);
-        this._target.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ScreencastVisibilityChanged, this._screencastVisibilityChanged, this);
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this._target);

[dgozman, 2016/07/14 16:29:29]

ditto

[eostroukhov-old, 2016/07/20 23:46:15]

Done.

+        if (resourceTreeModel) {
+            resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ScreencastFrame, this._screencastFrame, this);
+            resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.ScreencastVisibilityChanged, this._screencastVisibilityChanged, this);
+        }
 
         WebInspector.targetManager.addEventListener(WebInspector.TargetManager.Events.SuspendStateChanged, this._onSuspendStateChange, this);
         this._updateGlasspane();
@@ -741,7 +744,9 @@ WebInspector.ScreencastView.prototype = {
 
     _navigateReload: function()
     {
-        this._target.resourceTreeModel.reloadPage();
+        var resourceTreeModel = WebInspector.ResourceTreeModel.fromTarget(this._target);
+        if (resourceTreeModel)
+            resourceTreeModel.reloadPage();
     },
 
     _navigationUrlKeyUp: function(event)