Make zoom using ctrl+mouse wheel work in win aura. Windows -non-aura had a hack that was a layering…

content/browser/web_contents/web_contents_impl.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 420 matching lines @@
 
   // RenderWidgetHostDelegate --------------------------------------------------
 
   virtual void RenderWidgetDeleted(
       RenderWidgetHostImpl* render_widget_host) OVERRIDE;
   virtual bool PreHandleKeyboardEvent(
       const NativeWebKeyboardEvent& event,
       bool* is_keyboard_shortcut) OVERRIDE;
   virtual void HandleKeyboardEvent(
       const NativeWebKeyboardEvent& event) OVERRIDE;
+  virtual bool PreHandleWheelEvent(
+      const WebKit::WebMouseWheelEvent& event) OVERRIDE;
 
   // RenderViewHostManager::Delegate -------------------------------------------
 
   virtual bool CreateRenderViewForRenderManager(
       RenderViewHost* render_view_host, int opener_route_id) OVERRIDE;
   virtual void BeforeUnloadFiredFromRenderManager(
       bool proceed, const base::TimeTicks& proceed_time,
       bool* proceed_to_fire_unload) OVERRIDE;
   virtual void RenderViewGoneFromRenderManager(
       RenderViewHost* render_view_host) OVERRIDE;
@@ skipping 439 matching lines @@
   // Maps the ids of pending favicon downloads to their callbacks
   typedef std::map<int, FaviconDownloadCallback> FaviconDownloadMap;
   FaviconDownloadMap favicon_download_map_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_