Mac: Fix renderer idle cpu usage regression.

chrome/common/render_messages.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_COMMON_RENDER_MESSAGES_H_
 #define CHROME_COMMON_RENDER_MESSAGES_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 639 matching lines @@
   // Default file name to select in the dialog.
   FilePath default_file_name;
 };
 
 struct ViewMsg_ExtensionExtentsUpdated_Params {
   // A list of (extension_id, web_extent) pairs that describe the installed
   // extension apps and the URLs they cover.
   std::vector< std::pair<std::string, ExtensionExtent> > extension_apps;
 };
 
+// Values that may be OR'd together to form the 'flags' parameter of the
+// ViewMsg_EnablePreferredSizeChangedMode message.
+enum ViewHostMsg_EnablePreferredSizeChangedMode_Flags {
+  kPreferredSizeNothing,
+  kPreferredSizeWidth = 1 << 0,
+  // Requesting the height currently requires a polling loop in render_view.cc.
+  kPreferredSizeHeightThisIsSlow = 1 << 1,
+};
+
 namespace IPC {
 
 template <>
 struct ParamTraits<ResourceType::Type> {
   typedef ResourceType::Type param_type;
   static void Write(Message* m, const param_type& p) {
     m->WriteInt(p);
   }
   static bool Read(const Message* m, void** iter, param_type* p) {
     int type;
@@ skipping 1974 matching lines @@
     l->append(L")");
   }
 };
 
 }  // namespace IPC
 
 #define MESSAGES_INTERNAL_FILE "chrome/common/render_messages_internal.h"
 #include "ipc/ipc_message_macros.h"
 
 #endif  // CHROME_COMMON_RENDER_MESSAGES_H_