DevTools: Fix remote device debugging

Source/devtools/front_end/main/ScreencastApp.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.App}
  */
 WebInspector.ScreencastApp = function()
 {
     WebInspector.App.call(this);
 
-    var currentScreencastState = WebInspector.settings.createSetting("currentScreencastState", "");
-    var lastScreencastState = WebInspector.settings.createSetting("lastScreencastState", "");
+    var lastScreencastState = WebInspector.settings.createSetting("lastScreencastState", "disabled");

[dgozman, 2014/06/06 13:19:32]

Actually, it's better to start with "left", so users immediately see the feature
they came for. Sorry for that.

+    this._currentScreencastState = WebInspector.settings.createSetting("currentScreencastState", "disabled");
     this._toggleScreencastButton = new WebInspector.StatusBarStatesSettingButton(
         "screencast-status-bar-item",
         ["disabled", "left", "top"],
         [WebInspector.UIString("Disable screencast."), WebInspector.UIString("Switch to portrait screencast."), WebInspector.UIString("Switch to landscape screencast.")],
-        currentScreencastState.get(),
-        currentScreencastState,
+        this._currentScreencastState.get(),
+        this._currentScreencastState,
         lastScreencastState,
         this._onStatusBarButtonStateChanged.bind(this));
 };
 
 WebInspector.ScreencastApp.prototype = {
     createRootView: function()
     {
         var rootView = new WebInspector.RootView();
 
         this._rootSplitView = new WebInspector.SplitView(false, true, "InspectorView.screencastSplitViewState", 300, 300);
         this._rootSplitView.show(rootView.element);
 
         WebInspector.inspectorView.show(this._rootSplitView.sidebarElement());
         var target = /** @type {!WebInspector.Target} */ (WebInspector.targetManager.activeTarget());
         this._screencastView = new WebInspector.ScreencastView(target);
         this._screencastView.show(this._rootSplitView.mainElement());
 
-        this._onStatusBarButtonStateChanged("disabled");
+        this._onStatusBarButtonStateChanged(this._currentScreencastState.get());
         rootView.attachToBody();
     },
 
     presentUI: function()
     {
         WebInspector.App.prototype.presentUI.call(this);
         this._screencastView.initialize();
     },
 
     /**
      * @param {string} state
      */
     _onStatusBarButtonStateChanged: function(state)
     {
+        if (!this._rootSplitView)
+            return;
         if (state === "disabled") {
             this._rootSplitView.toggleResizer(this._rootSplitView.resizerElement(), false);
             this._rootSplitView.toggleResizer(WebInspector.inspectorView.topResizerElement(), false);
             this._rootSplitView.hideMain();
             return;
         }
 
         this._rootSplitView.setVertical(state === "left");
         this._rootSplitView.setSecondIsSidebar(true);
         this._rootSplitView.toggleResizer(this._rootSplitView.resizerElement(), true);
@@ skipping 16 matching lines @@
     /**
      * @return {?WebInspector.StatusBarButton}
      */
     button: function()
     {
         if (!(WebInspector.app instanceof WebInspector.ScreencastApp))
             return null;
         return /** @type {!WebInspector.ScreencastApp} */ (WebInspector.app)._toggleScreencastButton;
     }
 }