Remove obviously unneeded forward declarations in chrome/browser/[abef]*/*.h.

chrome/browser/extensions/extension_function_dispatcher.h

Index: chrome/browser/extensions/extension_function_dispatcher.h
diff --git a/chrome/browser/extensions/extension_function_dispatcher.h b/chrome/browser/extensions/extension_function_dispatcher.h
index 2a103287e46510f33da9f0526239698607df7615..e089e29727923f4cf0110f2646b7de788051590d 100644
--- a/chrome/browser/extensions/extension_function_dispatcher.h
+++ b/chrome/browser/extensions/extension_function_dispatcher.h
@@ -1,4 +1,4 @@
-// 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.
 
@@ -7,7 +7,6 @@
 #pragma once
 
 #include <string>
-#include <set>
 #include <vector>
 
 #include "base/ref_counted.h"
@@ -16,13 +15,10 @@
 
 class Browser;
 class Extension;
-class ExtensionDOMUI;
 class ExtensionFunction;
-class ExtensionHost;
 class ListValue;
 class Profile;
 class RenderViewHost;
-class RenderViewHostDelegate;
 class TabContents;
 
 // A factory function for creating new ExtensionFunction instances.