Make pinch-zoom work for OOP PDF

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.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_MIME_HANDLER_VIEW_MIME_HANDLER_VIEW_GUEST_H_
 #define EXTENSIONS_BROWSER_GUEST_VIEW_MIME_HANDLER_VIEW_MIME_HANDLER_VIEW_GUEST_H_
 
 #include "base/memory/weak_ptr.h"
 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/guest_view/guest_view.h"
@@ skipping 62 matching lines @@
   // content::BrowserPluginGuestDelegate implementation
   bool Find(int request_id,
             const base::string16& search_text,
             const blink::WebFindOptions& options) override;
 
   // WebContentsDelegate implementation.
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
+  bool PreHandleGestureEvent(content::WebContents* source,
+                             const blink::WebGestureEvent& event) override;
   void FindReply(content::WebContents* web_contents,
                  int request_id,
                  int number_of_matches,
                  const gfx::Rect& selection_rect,
                  int active_match_ordinal,
                  bool final_update) override;
   bool SaveFrame(const GURL& url, const content::Referrer& referrer) override;
 
   // content::WebContentsObserver implementation.
   void DocumentOnLoadCompletedInMainFrame() override;
@@ skipping 12 matching lines @@
   scoped_ptr<ExtensionFunctionDispatcher> extension_function_dispatcher_;
   scoped_ptr<StreamContainer> stream_;
   std::string view_id_;
 
   DISALLOW_COPY_AND_ASSIGN(MimeHandlerViewGuest);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_GUEST_VIEW_MIME_HANDLER_VIEW_MIME_HANDLER_VIEW_GUEST_H_