Make BrowserList::(Add|Remove)Observer add the observer to every desktop's browser list.

chrome/browser/ui/browser_list_impl.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_LIST_IMPL_H_
 #define CHROME_BROWSER_UI_BROWSER_LIST_IMPL_H_
 
 #include "base/observer_list.h"
+#include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/host_desktop.h"
 
 class Browser;
-class BrowserList;
 class Profile;
 
 namespace chrome {
 
 class BrowserListObserver;
 
 // Maintains a list of Browser objects present in a given HostDesktop (see
 // HostDesktopType).
 class BrowserListImpl {
  public:
   typedef std::vector<Browser*> BrowserVector;
   typedef BrowserVector::iterator iterator;
   typedef BrowserVector::const_iterator const_iterator;
   typedef BrowserVector::const_reverse_iterator const_reverse_iterator;
 
   static BrowserListImpl* GetInstance(HostDesktopType type);
 
   // Adds and removes browsers from the global list. The browser object should
   // be valid BEFORE these calls (for the benefit of observers), so notify and
   // THEN delete the object.
   void AddBrowser(Browser* browser);
   void RemoveBrowser(Browser* browser);
 
-  void AddObserver(BrowserListObserver* observer);
-  void RemoveObserver(BrowserListObserver* observer);
-
   // Called by Browser objects when their window is activated (focused).  This
   // allows us to determine what the last active Browser was.
   void SetLastActive(Browser* browser);
 
   Browser* GetLastActive() const;
 
   // Browsers are added to the list before they have constructed windows,
   // so the |window()| member function may return NULL.
   const_iterator begin() const { return browsers_.begin(); }
   const_iterator end() const { return browsers_.end(); }
@@ skipping 17 matching lines @@
   // Returns true if at least one incognito window is open.
   bool IsIncognitoWindowOpen() const;
 
   // Returns true if at least one incognito window is open for |profile|.
   bool IsIncognitoWindowOpenForProfile(Profile* profile) const;
 
  private:
   BrowserListImpl();
   ~BrowserListImpl();
 
+  // Only callable by BrowserList::(Add|Remove)Observer.
+  // TODO(gab): Merge BrowserListImpl into BrowserList removing the need for
+  // friend.
+  friend void BrowserList::AddObserver(chrome::BrowserListObserver*);
+  friend void BrowserList::RemoveObserver(chrome::BrowserListObserver*);
+  void AddObserver(BrowserListObserver* observer);
+  void RemoveObserver(BrowserListObserver* observer);
+
   // Helper method to remove a browser instance from a list of browsers
   void RemoveBrowserFrom(Browser* browser, BrowserVector* browser_list);
 
   ObserverList<BrowserListObserver> observers_;
 
   BrowserVector browsers_;
   BrowserVector last_active_browsers_;
 
   // Nothing fancy, since we only have two HDTs.
   static BrowserListImpl* native_instance_;
   static BrowserListImpl* ash_instance_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserListImpl);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_BROWSER_LIST_IMPL_H_