Simplify the Observer pattern used in the BrowserList.

chrome/browser/browser_list.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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_BROWSER_LIST_H_
 #define CHROME_BROWSER_BROWSER_LIST_H_
 
 #include <vector>
 
+#include "base/observer_list.h"
 #include "chrome/browser/browser.h"
 
 // Stores a list of all Browser objects.
 class BrowserList {
  public:
-  typedef std::vector<Browser*> list_type;
-  typedef list_type::iterator iterator;
-  typedef list_type::const_iterator const_iterator;
-  typedef list_type::const_reverse_iterator const_reverse_iterator;
+  typedef std::vector<Browser*> BrowserVector;
+  typedef BrowserVector::iterator iterator;
+  typedef BrowserVector::const_iterator const_iterator;
+  typedef BrowserVector::const_reverse_iterator const_reverse_iterator;
 
   // It is not allowed to change the global window list (add or remove any
   // browser windows while handling observer callbacks.
   class Observer {
    public:
     // Called immediately after a browser is added to the list
     virtual void OnBrowserAdded(const Browser* browser) = 0;
 
     // Called immediately before a browser is removed from the list
     virtual void OnBrowserRemoving(const Browser* browser) = 0;
@@ skipping 71 matching lines @@
 
   // Begins shutdown of the application when the Windows session is ending.
   static void WindowsSessionEnding();
 
   // Returns true if there is at least one Browser with the specified profile.
   static bool HasBrowserWithProfile(Profile* profile);
 
   // Returns true if browser is in persistent mode and false otherwise.
   static bool IsInPersistentMode();
 
-  static const_iterator begin() {
-    return browsers_.begin();
-  }
+  static const_iterator begin() { return browsers_.begin(); }
+  static const_iterator end() { return browsers_.end(); }
 
-  static const_iterator end() {
-    return browsers_.end();
-  }
-
-  static size_t size() {
-    return browsers_.size();
-  }
+  static size_t size() { return browsers_.size(); }
 
   // Returns iterated access to list of open browsers ordered by when
   // they were last active. The underlying data structure is a vector
   // and we push_back on recent access so a reverse iterator gives the
   // latest accessed browser first.
   static const_reverse_iterator begin_last_active() {
     return last_active_browsers_.rbegin();
   }
 
   static const_reverse_iterator end_last_active() {
     return last_active_browsers_.rend();
   }
 
   // Return the number of browsers with the following profile which are
   // currently open.
   static size_t GetBrowserCount(Profile* p);
 
   // Return the number of browsers with the following profile and type which are
   // currently open.
   static size_t GetBrowserCountForType(Profile* p, Browser::Type type);
 
   // Returns true if at least one off the record session is active.
   static bool IsOffTheRecordSessionActive();
 
   // Called when the last browser is closed.
   static void AllBrowsersClosed();
 
  private:
   // Helper method to remove a browser instance from a list of browsers
-  static void RemoveBrowserFrom(Browser* browser, list_type* browser_list);
+  static void RemoveBrowserFrom(Browser* browser, BrowserVector* browser_list);
 
-  static list_type browsers_;
-  static std::vector<Observer*> observers_;
-  static list_type last_active_browsers_;
+  static BrowserVector browsers_;
+  static BrowserVector last_active_browsers_;
+  static ObserverList<Observer> observers_;
 };
 
 class TabContents;
 
 // Iterates through all web view hosts in all browser windows. Because the
 // renderers act asynchronously, getting a host through this interface does
 // not guarantee that the renderer is ready to go. Doing anything to affect
 // browser windows or tabs while iterating may cause incorrect behavior.
 //
 // Example:
@@ skipping 43 matching lines @@
   // tab index into the current Browser of the current web view
   int web_view_index_;
 
   // Current TabContents, or NULL if we're at the end of the list. This can
   // be extracted given the browser iterator and index, but it's nice to cache
   // this since the caller may access the current host many times.
   TabContents* cur_;
 };
 
 #endif  // CHROME_BROWSER_BROWSER_LIST_H_