[Extensions UI] Clean up extension icon generation

chrome/browser/ui/cocoa/extensions/browser_action_button.h

Index: chrome/browser/ui/cocoa/extensions/browser_action_button.h
diff --git a/chrome/browser/ui/cocoa/extensions/browser_action_button.h b/chrome/browser/ui/cocoa/extensions/browser_action_button.h
index cbf9a97d8e034fa276abe95aedfb18a743b7e04a..55b626455837bfa7839432bca50dbf1416653ced 100644
--- a/chrome/browser/ui/cocoa/extensions/browser_action_button.h
+++ b/chrome/browser/ui/cocoa/extensions/browser_action_button.h
@@ -96,14 +96,10 @@ extern NSString* const kBrowserActionButtonDragEndNotification;
  @private
   // The controller for the browser actions bar that owns the button. Weak.
   BrowserActionsController* browserActionsController_;
-
-  // The view controller for the parent button. Weak.
-  ToolbarActionViewController* viewController_;
 }
 
 @property(assign, nonatomic)
     BrowserActionsController* browserActionsController;
-@property(readwrite, nonatomic) ToolbarActionViewController* viewController;
 
 @end