InstantExtended: record Instant NTP load times.

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"
@@ skipping 11 matching lines @@
 #include "chrome/browser/ui/app_list/app_list_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/omnibox/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/search_ipc_router_policy_impl.h"
+#include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/tabs/tab_strip_model_utils.h"
 #include "chrome/browser/ui/webui/ntp/ntp_user_data_logger.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_type.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/user_metrics.h"
@@ skipping 74 matching lines @@
   if (!contents)
     return;
 
   Browser* browser = chrome::FindBrowserWithWebContents(contents);
   if (!browser)
     return;
   browser->OnWebContentsInstantSupportDisabled(contents);
 #endif
 }
 
+// Called when an NTP finishes loading. If the load start time was noted,
+// calculates and logs the total load time.
+void RecordNewTabLoadTime(content::WebContents* contents) {
+  CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(contents);
+  if (core_tab_helper->new_tab_start_time().is_null())
+    return;
+
+  base::TimeDelta duration =
+      base::TimeTicks::Now() - core_tab_helper->new_tab_start_time();
+  UMA_HISTOGRAM_TIMES("Tab.NewTabOnload", duration);
+  core_tab_helper->set_new_tab_start_time(base::TimeTicks());

[Jered, 2014/01/02 20:12:41]

Why are you resetting the start time here?

[samarth, 2014/01/04 01:22:38]

This is because not all code paths that open the NTP record the start time
(IIRC, only if you use ctrl+T or if you click on the new tab button).  And we
use the existence of a non-null start here to decide whether the start time was
recorded. So if we didn't clear here and then opened an NTP in the same tab
again by typing chrome://newtab, it would record the wrong time.

+}
+
 }  // namespace
 
 SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
     : WebContentsObserver(web_contents),
       is_search_enabled_(chrome::IsInstantExtendedAPIEnabled()),
       user_input_in_progress_(false),
       web_contents_(web_contents),
       ipc_router_(web_contents, this,
                   make_scoped_ptr(new SearchIPCRouterPolicyImpl(web_contents))
                       .PassAs<SearchIPCRouter::Policy>()),
@@ skipping 147 matching lines @@
     RedirectToLocalNTP();
     RecordCacheableNTPLoadHistogram(false);
   }
 }
 
 void SearchTabHelper::DidFinishLoad(
     int64 /* frame_id */,
     const GURL&  /* validated_url */,
     bool is_main_frame,
     content::RenderViewHost* /* render_view_host */) {
-  if (is_main_frame)
+  if (is_main_frame) {
+    if (chrome::IsInstantNTP(web_contents_))
+      RecordNewTabLoadTime(web_contents_);
+
     DetermineIfPageSupportsInstant();
+  }
 }
 
 void SearchTabHelper::NavigationEntryCommitted(
     const content::LoadCommittedDetails& load_details) {
   if (!is_search_enabled_)
     return;
 
   if (!load_details.is_main_frame)
     return;
 
@@ skipping 263 matching lines @@
 void SearchTabHelper::RedirectToLocalNTP() {
   // Extra parentheses to declare a variable.
   content::NavigationController::LoadURLParams load_params(
       (GURL(chrome::kChromeSearchLocalNtpUrl)));
   load_params.referrer = content::Referrer();
   load_params.transition_type = content::PAGE_TRANSITION_SERVER_REDIRECT;
   // Don't push a history entry.
   load_params.should_replace_current_entry = true;
   web_contents_->GetController().LoadURLWithParams(load_params);
 }