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

chrome/browser/devtools/devtools_window.h

Index: chrome/browser/devtools/devtools_window.h
diff --git a/chrome/browser/devtools/devtools_window.h b/chrome/browser/devtools/devtools_window.h
index 5e201ef44eefd43f7bf4833b13102bf7729c548c..fd7f43010b36322a1cc0a0b435d257963057f9b4 100644
--- a/chrome/browser/devtools/devtools_window.h
+++ b/chrome/browser/devtools/devtools_window.h
@@ -326,6 +326,9 @@ class DevToolsWindow : private content::NotificationObserver,
   virtual void SearchInPath(int request_id,
                             const std::string& file_system_path,
                             const std::string& query) OVERRIDE;
+  virtual void ZoomIn() OVERRIDE;
+  virtual void ZoomOut() OVERRIDE;
+  virtual void ResetZoom() OVERRIDE;
 
   // DevToolsFileHelper callbacks.
   void FileSavedAs(const std::string& url);