[DevTools] Issue zoom from DevToolsWindow instead of browser commands.

chrome/browser/devtools/devtools_embedder_message_dispatcher.h

 // Copyright 2013 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_BROWSER_DEVTOOLS_DEVTOOLS_EMBEDDER_MESSAGE_DISPATCHER_H_
 #define CHROME_BROWSER_DEVTOOLS_DEVTOOLS_EMBEDDER_MESSAGE_DISPATCHER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 36 matching lines @@
     virtual void AddFileSystem() = 0;
     virtual void RemoveFileSystem(const std::string& file_system_path) = 0;
     virtual void UpgradeDraggedFileSystemPermissions(
         const std::string& file_system_url) = 0;
     virtual void IndexPath(int request_id,
                            const std::string& file_system_path) = 0;
     virtual void StopIndexing(int request_id) = 0;
     virtual void SearchInPath(int request_id,
                               const std::string& file_system_path,
                               const std::string& query) = 0;
+    virtual void ZoomIn() = 0;
+    virtual void ZoomOut() = 0;
+    virtual void ResetZoom() = 0;
   };
 
   explicit DevToolsEmbedderMessageDispatcher(Delegate* delegate);
 
   ~DevToolsEmbedderMessageDispatcher();
 
   std::string Dispatch(const std::string& method, base::ListValue* params);
 
  private:
   typedef base::Callback<bool(const base::ListValue&)> Handler;
   void RegisterHandler(const std::string& method, const Handler& handler);
 
   typedef std::map<std::string, Handler> HandlerMap;
   HandlerMap handlers_;
 };
 
 #endif  // CHROME_BROWSER_DEVTOOLS_DEVTOOLS_EMBEDDER_MESSAGE_DISPATCHER_H_