Add zoom extension API

chrome/renderer/render_view.h

 // Copyright (c) 2011 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 CHROME_RENDERER_RENDER_VIEW_H_
 #define CHROME_RENDERER_RENDER_VIEW_H_
 #pragma once
 
 #include <deque>
 #include <map>
@@ skipping 362 matching lines @@
                                          int32 width,
                                          int32 height,
                                          TransportDIB::Handle transport_dib);
   void AcceleratedSurfaceBuffersSwapped(gfx::PluginWindowHandle window,
                                         uint64 surface_id);
 #endif
 
   void RegisterPluginDelegate(WebPluginDelegateProxy* delegate);
   void UnregisterPluginDelegate(WebPluginDelegateProxy* delegate);
 
+  // Respond to a zoom request from the browser process
+  void zoomLevelChanged(int request_id);
+
   // IPC::Channel::Listener implementation -------------------------------------
 
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
   // WebKit::WebWidgetClient implementation ------------------------------------
 
   // Most methods are handled by RenderWidget.
   virtual void didFocus();
   virtual void didBlur();
   virtual void show(WebKit::WebNavigationPolicy policy);
@@ skipping 538 matching lines @@
   void OnSetDOMUIProperty(const std::string& name, const std::string& value);
   void OnSetEditCommandsForNextKeyEvent(const EditCommands& edit_commands);
   void OnSetInitialFocus(bool reverse);
   void OnScrollFocusedEditableNodeIntoView();
   void OnSetPageEncoding(const std::string& encoding_name);
   void OnSetRendererPrefs(const RendererPreferences& renderer_prefs);
   void OnSetupDevToolsClient();
 #if defined(OS_MACOSX)
   void OnSetWindowVisibility(bool visible);
 #endif
-  void OnSetZoomLevel(double zoom_level);
+  void OnSetZoomLevel(int request_id, double zoom_level);
   void OnSetZoomLevelForLoadingURL(const GURL& url, double zoom_level);
   void OnShouldClose();
   void OnStop();
   void OnStopFinding(const ViewMsg_StopFinding_Params& params);
   void OnThemeChanged();
   void OnToggleSpellCheck();
   void OnToggleSpellPanel(bool is_currently_visible);
   void OnUndo();
   void OnUpdateBrowserWindowId(int window_id);
   void OnUpdateTargetURLAck();
@@ skipping 524 matching lines @@
   // bunch of stuff, you should probably create a helper class and put your
   // data and methods on that to avoid bloating RenderView more.  You can use
   // the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderView);
 };
 
 #endif  // CHROME_RENDERER_RENDER_VIEW_H_