Fixed and reenabled the flaky test "WebViewAPITest.TestAutosizeAfterNavigation".

extensions/browser/guest_view/guest_view_base.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_GUEST_VIEW_GUEST_VIEW_BASE_H_
 #define EXTENSIONS_BROWSER_GUEST_VIEW_GUEST_VIEW_BASE_H_
 
 #include <queue>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 254 matching lines @@
   void SetAttachParams(const base::DictionaryValue& params);
   void SetOpener(GuestViewBase* opener);
 
   // BrowserPluginGuestDelegate implementation.
   content::WebContents* CreateNewGuestWindow(
       const content::WebContents::CreateParams& create_params) final;
   void DidAttach(int guest_proxy_routing_id) final;
   void DidDetach() final;
   void ElementSizeChanged(const gfx::Size& size) final;
   content::WebContents* GetOwnerWebContents() const final;
-  void GuestSizeChanged(const gfx::Size& old_size,
-                        const gfx::Size& new_size) final;
+  void GuestSizeChanged(const gfx::Size& new_size) final;
   void RegisterDestructionCallback(const DestructionCallback& callback) final;
   void SetGuestSizer(content::GuestSizer* guest_sizer) final;
   void WillAttach(content::WebContents* embedder_web_contents,
                   int browser_plugin_instance_id,
                   bool is_full_page_plugin) final;
 
   // ui_zoom::ZoomObserver implementation.
   void OnZoomChanged(
       const ui_zoom::ZoomController::ZoomChangedEventData& data) override;
 
@@ skipping 127 matching lines @@
   // This is used to ensure pending tasks will not fire after this object is
   // destroyed.
   base::WeakPtrFactory<GuestViewBase> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GuestViewBase);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_GUEST_VIEW_GUEST_VIEW_BASE_H_