Zoom Extension API (chrome)

chrome/browser/ui/zoom/zoom_observer.h

Index: chrome/browser/ui/zoom/zoom_observer.h
diff --git a/chrome/browser/ui/zoom/zoom_observer.h b/chrome/browser/ui/zoom/zoom_observer.h
index 54f52e186b525c9964f0ea51f7b9cfbd98e94db1..2793e806a9137350a511e048cb3b0a54ebb38bfc 100644
--- a/chrome/browser/ui/zoom/zoom_observer.h
+++ b/chrome/browser/ui/zoom/zoom_observer.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_UI_ZOOM_ZOOM_OBSERVER_H_
 #define CHROME_BROWSER_UI_ZOOM_ZOOM_OBSERVER_H_
 
+#include "chrome/browser/ui/zoom/zoom_controller.h"
+
 namespace content {
 class WebContents;
 }
@@ -14,7 +16,13 @@ class ZoomObserver {
  public:
   // Notification that the zoom percentage has changed.
   virtual void OnZoomChanged(content::WebContents* source,
-                             bool can_show_bubble) = 0;
+                             bool can_show_bubble) {}
+
+  // Notification that a zoom change has been initiated for |web_contents|.
+  virtual void OnZoomChangeInitiated(content::WebContents* web_contents,
+                                     double old_zoom_level,
+                                     double new_zoom_level,
+                                     ZoomController::ZoomMode zoom_mode) {}
 
  protected:
   virtual ~ZoomObserver() {}