Implement sidebar support for extension action popups

chrome/browser/ui/cocoa/browser_window_cocoa.h

Index: chrome/browser/ui/cocoa/browser_window_cocoa.h
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.h b/chrome/browser/ui/cocoa/browser_window_cocoa.h
index 5c2b165cf00de711cfce6d45535c058e10db935b..a35d7713990428576f4eef33073f7934fc032f68 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.h
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.h
@@ -36,6 +36,7 @@ class BrowserWindowCocoa
     : public BrowserWindow,
       public ExclusiveAccessContext,
       public extensions::ExtensionKeybindingRegistry::Delegate,
+      public content::NotificationObserver,
       public SearchModelObserver {
  public:
   BrowserWindowCocoa(Browser* browser,
@@ -157,6 +158,11 @@ class BrowserWindowCocoa
   int GetRenderViewHeightInsetWithDetachedBookmarkBar() override;
   void ExecuteExtensionCommand(const extensions::Extension* extension,
                                const extensions::Command& command) override;
+  // content::NotificationObserver overrides:
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
   ExclusiveAccessContext* GetExclusiveAccessContext() override;
 
   // ExclusiveAccessContext interface
@@ -184,7 +190,8 @@ class BrowserWindowCocoa
 
  private:
   NSWindow* window() const;  // Accessor for the (current) |NSWindow|.
-
+  void UpdateSidebarForContents(content::WebContents* tab_contents);
+  content::NotificationRegistrar registrar_;
   Browser* browser_;  // weak, owned by controller
   BrowserWindowController* controller_;  // weak, owns us
   base::scoped_nsobject<NSString> pending_window_title_;