Zoom Extension API (chrome)

chrome/browser/ui/browser.h

 // Copyright (c) 2012 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_UI_BROWSER_H_
 #define CHROME_BROWSER_UI_BROWSER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 735 matching lines @@
 
   // In-progress download termination handling /////////////////////////////////
 
   // Called when the window is closing to check if potential in-progress
   // downloads should prevent it from closing.
   // Returns true if the window can close, false otherwise.
   bool CanCloseWithInProgressDownloads();
 
   // Assorted utility functions ///////////////////////////////////////////////
 
+  // Sets/Clears this browser object as an observer on helpers of the web
+  // contents.
+  void SetAsObserver(content::WebContents* web_contents);

[sky, 2014/06/24 16:23:41]

The name and this function and description imply something very generic. Yet the
implementation is just about zoom. Since the implementation of these functions
is just a one liner I don't see any value in them.

Maybe I'm missing something, but AFAICT the only changes you should need in
browser.cc are to change 2195 (old) to something like:

if (delegate)
  ZoomController::FromWebContents(web_contents)->AddObserver(delegate);
else
  ZoomController::FromWebContents(web_contents)->RemoveObserver(this);

The latter is slightly unfortunate. It could be clarified by making the function
take a boolean instead of a delegate.

[wjmaclean, 2014/06/24 18:04:07]

It was the latter case that caused me to create the separate functions, but if
it's ok to change to using a boolean then that makes it clear that the delegate
is only ever 'this' and we are setting/clearing.

+  void ClearAsObserver(content::WebContents* web_contents);
+
   // Sets the specified browser as the delegate of the WebContents and all the
   // associated tab helpers that are needed.
   void SetAsDelegate(content::WebContents* web_contents, Browser* delegate);
 
   // Shows the Find Bar, optionally selecting the next entry that matches the
   // existing search string for that Tab. |forward_direction| controls the
   // search direction.
   void FindInPage(bool find_next, bool forward_direction);
 
   // Closes the frame.
@@ skipping 169 matching lines @@
   base::WeakPtrFactory<Browser> weak_factory_;
 
   scoped_ptr<BrowserContentTranslateDriverObserver> translate_driver_observer_;
 
   scoped_ptr<chrome::ValidationMessageBubble> validation_message_bubble_;
 
   DISALLOW_COPY_AND_ASSIGN(Browser);
 };
 
 #endif  // CHROME_BROWSER_UI_BROWSER_H_