Attempt four at landing the "histogram.h removed from message_loop.h" patch.

chrome/browser/plugin_process_host.h

 // 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_PLUGIN_PROCESS_HOST_H_
 #define CHROME_BROWSER_PLUGIN_PROCESS_HOST_H_
 
 #include "build/build_config.h"
 
 #include <queue>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/scoped_ptr.h"
-#include "base/task.h"
 #include "chrome/browser/browser_child_process_host.h"
 #include "chrome/browser/net/resolve_proxy_msg_helper.h"
 #include "chrome/browser/renderer_host/resource_message_filter.h"
 #include "gfx/native_widget_types.h"
 #include "ipc/ipc_channel_handle.h"
 #include "webkit/glue/plugins/webplugininfo.h"
 
 class URLRequestContext;
 struct ViewHostMsg_Resource_Request;
 class GURL;
@@ skipping 145 matching lines @@
   // Tracks modal windows currently visible.
   std::set<uint32> plugin_modal_windows_set_;
   // Tracks the current visibility of the cursor.
   bool plugin_cursor_visible_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(PluginProcessHost);
 };
 
 #endif  // CHROME_BROWSER_PLUGIN_PROCESS_HOST_H_