histogram synchronizer code between renderer and browser for UMA and about_histogram

chrome/browser/browser_about_handler.cc

 // Copyright (c) 2006-2008 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.
 
 #include "chrome/browser/browser_about_handler.h"
 
 #include <string>
 #include <vector>
 
 #include "app/resource_bundle.h"
 #include "base/file_version_info.h"
 #include "base/histogram.h"
 #include "base/platform_thread.h"
 #include "base/stats_table.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/thread.h"
 #include "base/tracked_objects.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/dom_ui/chrome_url_data_manager.h"
 #include "chrome/browser/memory_details.h"
 #include "chrome/browser/net/dns_global.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/common/histogram_synchronizer.h"
 #include "chrome/common/jstemplate_builder.h"
 #include "chrome/common/l10n_util.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/pref_service.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/about_handler.h"
 #include "googleurl/src/gurl.h"
 #include "grit/browser_resources.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/locale_settings.h"
 #include "webkit/glue/webkit_glue.h"
 #ifdef CHROME_V8
 #include "v8/include/v8.h"
 #endif
 
 #if defined(OS_WIN)
 #include "chrome/browser/views/about_ipc_dialog.h"
 #include "chrome/browser/views/about_network_dialog.h"
 #endif
 
+using base::Time;
+using base::TimeDelta;
+
 namespace {
 
 // The paths used for the about pages.
 const char kCachePath[] = "cache";
 const char kDnsPath[] = "dns";
 const char kHistogramsPath[] = "histograms";
 const char kObjectsPath[] = "objects";
 const char kMemoryRedirectPath[] = "memory-redirect";
 const char kMemoryPath[] = "memory";
 const char kPluginsPath[] = "plugins";
@@ skipping 72 matching lines @@
   return credits_html;
 }
 
 std::string AboutDns() {
   std::string data;
   chrome_browser_net::DnsPrefetchGetHtmlInfo(&data);
   return data;
 }
 
 std::string AboutHistograms(const std::string& query) {
+  TimeDelta wait_time = TimeDelta::FromMilliseconds(1000);
+
+  HistogramSynchronizer* current_synchronizer =
+      HistogramSynchronizer::CurrentSynchronizer();
+  DCHECK(current_synchronizer != NULL);
+  current_synchronizer->FetchRendererHistogramsSynchronously(wait_time);
+
   std::string data;
-  for (RenderProcessHost::iterator it = RenderProcessHost::begin();
-       it != RenderProcessHost::end(); ++it) {
-    it->second->Send(new ViewMsg_GetRendererHistograms());
-  }
-
-  // TODO(raman): Delay page layout until we get respnoses
-  // back from renderers, and not have to use a fixed size delay.
-  PlatformThread::Sleep(1000);
-
   StatisticsRecorder::WriteHTMLGraph(query, &data);
   return data;
 }
 
 std::string AboutLinuxSplash() {
   static const std::string linux_splash_html =
       ResourceBundle::GetSharedInstance().GetDataResource(
           IDR_LINUX_SPLASH_HTML);
 
   return linux_splash_html;
@@ skipping 483 matching lines @@
     AboutIPCDialog::RunDialog();
     return true;
   }
 #endif
 
 #else
   // TODO(port) Implement this.
 #endif
   return false;
 }