Adds a new UMA histogram to measure the NTP load time since navigation

chrome/browser/ui/search/search_tab_helper.cc

 // Copyright 2012 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/ui/search/search_tab_helper.h"
 
 #include <set>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_service.h"
 #include "chrome/browser/search/instant_service_factory.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/ui/app_list/app_list_util.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/location_bar/location_bar.h"
 #include "chrome/browser/ui/omnibox/omnibox_edit_model.h"
 #include "chrome/browser/ui/omnibox/omnibox_popup_model.h"
 #include "chrome/browser/ui/omnibox/omnibox_view.h"
 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
+#include "chrome/browser/ui/search/instant_tab.h"
 #include "chrome/browser/ui/search/search_ipc_router_policy_impl.h"
 #include "chrome/browser/ui/search/search_tab_helper_delegate.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 #include "chrome/browser/ui/webui/ntp/ntp_user_data_logger.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/generated_resources.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/search/search.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "content/public/browser/navigation_controller.h"
@@ skipping 355 matching lines @@
 void SearchTabHelper::OnSetVoiceSearchSupport(bool supports_voice_search) {
   model_.SetVoiceSearchSupported(supports_voice_search);
 }
 
 void SearchTabHelper::ThemeInfoChanged(const ThemeBackgroundInfo& theme_info) {
   ipc_router_.SendThemeBackgroundInfo(theme_info);
 }
 
 void SearchTabHelper::MostVisitedItemsChanged(
     const std::vector<InstantMostVisitedItem>& items) {
+  // When most visited change, the NTP usually reloads the tiles. This means
+  // our metrics get inconsistent. So we'd rather emit stats now.
+  InstantTab::EmitNtpStatistics(web_contents_);
   ipc_router_.SendMostVisitedItems(items);
 }
 
 void SearchTabHelper::OmniboxStartMarginChanged(int omnibox_start_margin) {
   ipc_router_.SetOmniboxStartMargin(omnibox_start_margin);
 }
 
 void SearchTabHelper::FocusOmnibox(OmniboxFocusState state) {
 // TODO(kmadhusu): Move platform specific code from here and get rid of #ifdef.
 #if !defined(OS_ANDROID)
@@ skipping 177 matching lines @@
 
 bool SearchTabHelper::IsInputInProgress() const {
   OmniboxView* omnibox = GetOmniboxView();
   return !model_.mode().is_ntp() && omnibox &&
       omnibox->model()->focus_state() == OMNIBOX_FOCUS_VISIBLE;
 }
 
 OmniboxView* SearchTabHelper::GetOmniboxView() const {
   return delegate_ ? delegate_->GetOmniboxView() : NULL;
 }