histogram synchronizer code between renderer and browser for UMA and about_histogram

chrome/common/render_messages_internal.h

 // Copyright (c) 2009 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.
 
 // This header is meant to be included in multiple passes, hence no traditional
 // header guard.
 // See ipc_message_macros.h for explanation of the macros and passes.
 
 #include <string>
 #include <vector>
@@ skipping 437 matching lines @@
   // onunload event handler.  Expects a ClosePage_ACK message when finished.
   IPC_MESSAGE_ROUTED2(ViewMsg_ClosePage,
                       int /* new_render_process_host_id */,
                       int /* new_request_id */)
 
   // Asks the renderer to send back stats on the WebCore cache broken down by
   // resource types.
   IPC_MESSAGE_CONTROL0(ViewMsg_GetCacheResourceStats)
 
   // Asks the renderer to send back Histograms.
-  IPC_MESSAGE_CONTROL0(ViewMsg_GetRendererHistograms)
+  IPC_MESSAGE_CONTROL1(ViewMsg_GetRendererHistograms,
+                       int /* sequence number of Renderer Histograms. */)
 
   // Notifies the renderer about ui theme changes
   IPC_MESSAGE_ROUTED0(ViewMsg_ThemeChanged)
 
   // Notifies the renderer that a paint is to be generated for the rectangle
   // passed in.
   IPC_MESSAGE_ROUTED1(ViewMsg_Repaint,
                       gfx::Size /* The view size to be repainted */)
 
   // Posts a message to the renderer.
@@ skipping 604 matching lines @@
 
   IPC_MESSAGE_ROUTED2(ViewHostMsg_ToolsAgentMsg,
                       int, /* tools msg type */
                       std::wstring  /* body */)
 
   // Send back a string to be recorded by UserMetrics.
   IPC_MESSAGE_ROUTED1(ViewHostMsg_UserMetricsRecordAction,
                       std::wstring /* action */)
 
   // Send back histograms as vector of pickled-histogram strings.
-  IPC_MESSAGE_CONTROL1(ViewHostMsg_RendererHistograms, std::vector<std::string>)
+  IPC_MESSAGE_CONTROL2(ViewHostMsg_RendererHistograms,
+                       int, /* sequence number of Renderer Histograms. */
+                       std::vector<std::string>)
 
   // Request for a DNS prefetch of the names in the array.
   // NameList is typedef'ed std::vector<std::string>
   IPC_MESSAGE_CONTROL1(ViewHostMsg_DnsPrefetch,
                       std::vector<std::string> /* hostnames */)
 
   // Notifies when default plugin updates status of the missing plugin.
   IPC_MESSAGE_ROUTED1(ViewHostMsg_MissingPluginStatus,
                       int /* status */)
 
@@ skipping 252 matching lines @@
   // by ViewHostMsg_OpenChannelToExtension.
   IPC_MESSAGE_ROUTED2(ViewHostMsg_ExtensionPostMessage,
                       int /* port_id */,
                       std::string /* message */)
 
   // Message to show a popup menu using native cocoa controls (Mac only).
   IPC_MESSAGE_ROUTED1(ViewHostMsg_ShowPopup,
                       ViewHostMsg_ShowPopup_Params)
 
 IPC_END_MESSAGES(ViewHost)