[DevTools] Implement dock to left.

third_party/WebKit/Source/devtools/front_end/emulation/AdvancedApp.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.
 /**
  * @implements {Common.App}
  * @unrestricted
  */
 Emulation.AdvancedApp = class {
   constructor() {
     Components.dockController.addEventListener(
@@ skipping 10 matching lines @@
   }
 
   /**
    * @override
    * @param {!Document} document
    */
   presentUI(document) {
     var rootView = new UI.RootView();
 
     this._rootSplitWidget = new UI.SplitWidget(false, true, 'InspectorView.splitViewState', 555, 300, true);
-    this._rootSplitWidget.element.classList.add('root-split-widget');
     this._rootSplitWidget.show(rootView.element);
     this._rootSplitWidget.setSidebarWidget(UI.inspectorView);
     this._rootSplitWidget.setDefaultFocusedChild(UI.inspectorView);
     UI.inspectorView.setOwnerSplit(this._rootSplitWidget);
 
     this._inspectedPagePlaceholder = new Emulation.InspectedPagePlaceholder();
     this._inspectedPagePlaceholder.addEventListener(
         Emulation.InspectedPagePlaceholder.Events.Update, this._onSetInspectedPageBounds.bind(this), this);
     this._deviceModeView = new Emulation.DeviceModeWrapper(this._inspectedPagePlaceholder);
 
@@ skipping 91 matching lines @@
       this._updateForDocked(/** @type {string} */ (event.data.to));
     }
     this._changingDockSide = false;
     this._inspectedPagePlaceholder.update();
   }
 
   /**
    * @param {string} dockSide
    */
   _updateForDocked(dockSide) {
-    this._rootSplitWidget.setVertical(dockSide === Components.DockController.State.DockedToRight);
+    this._rootSplitWidget.resizerElement().style.transform =
+        dockSide === Components.DockController.State.DockedToRight ?
+        'translateX(2px)' :
+        dockSide === Components.DockController.State.DockedToLeft ? 'translateX(-2px)' : '';
+    this._rootSplitWidget.setVertical(
+        dockSide === Components.DockController.State.DockedToRight ||
+        dockSide === Components.DockController.State.DockedToLeft);
     this._rootSplitWidget.setSecondIsSidebar(
         dockSide === Components.DockController.State.DockedToRight ||
         dockSide === Components.DockController.State.DockedToBottom);
     this._rootSplitWidget.toggleResizer(this._rootSplitWidget.resizerElement(), true);
     this._rootSplitWidget.toggleResizer(
         UI.inspectorView.topResizerElement(), dockSide === Components.DockController.State.DockedToBottom);
     this._rootSplitWidget.showBoth();
   }
 
   _updateForUndocked() {
@@ skipping 33 matching lines @@
  */
 Emulation.AdvancedAppProvider = class {
   /**
    * @override
    * @return {!Common.App}
    */
   createApp() {
     return Emulation.AdvancedApp._instance();
   }
 };