[NoStatePrefetch] Add performance histograms.

chrome/browser/prerender/prerender_manager.cc

 // Copyright (c) 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/prerender/prerender_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <functional>
@@ skipping 127 matching lines @@
 };
 
 // static
 int PrerenderManager::prerenders_per_session_count_ = 0;
 
 // static
 PrerenderManager::PrerenderManagerMode PrerenderManager::mode_ =
     PRERENDER_MODE_ENABLED;
 
 struct PrerenderManager::NavigationRecord {
-  NavigationRecord(const GURL& url, base::TimeTicks time)
-      : url(url),
-        time(time) {
-  }
+  NavigationRecord(const GURL& url, base::TimeTicks time, Origin origin)
+      : url(url), time(time), origin(origin) {}
 
   GURL url;
   base::TimeTicks time;
+  Origin origin;
 };
 
 PrerenderManager::PrerenderManager(Profile* profile)
     : profile_(profile),
       prerender_contents_factory_(PrerenderContents::CreateFactory()),
       last_prerender_start_time_(
           GetCurrentTimeTicks() -
           base::TimeDelta::FromMilliseconds(kMinTimeBetweenPrerendersMs)),
       prerender_history_(new PrerenderHistory(kHistoryLength)),
       histograms_(new PrerenderHistograms()),
@@ skipping 396 matching lines @@
                                               is_redirect, is_no_store);
 }
 
 void PrerenderManager::RecordPrefetchRedirectCount(Origin origin,
                                                    bool is_main_resource,
                                                    int redirect_count) {
   histograms_->RecordPrefetchRedirectCount(origin, is_main_resource,
                                            redirect_count);
 }
 
+void PrerenderManager::RecordFirstContentfulPaint(const GURL& url,
+                                                  bool is_no_store,
+                                                  base::TimeDelta time) {
+  CleanUpOldNavigations(&prefetches_, base::TimeDelta::FromMinutes(30));
+
+  // Compute the prefetch age.
+  base::TimeDelta prefetch_age;
+  Origin origin = ORIGIN_NONE;
+  for (auto it = prefetches_.crbegin(); it != prefetches_.crend(); ++it) {
+    if (it->url == url) {
+      prefetch_age = GetCurrentTimeTicks() - it->time;
+      origin = it->origin;
+      break;
+    }
+  }
+
+  histograms_->RecordFirstContentfulPaint(origin, is_no_store, time,
+                                          prefetch_age);
+
+  // Loading a prefetched URL resets the revalidation bypass. Remove the url
+  // from the prefetch list for more accurate metrics.
+  prefetches_.erase(
+      std::remove_if(prefetches_.begin(), prefetches_.end(),
+                     [url](const NavigationRecord& r) { return r.url == url; }),
+      prefetches_.end());
+}
+
 // static
 PrerenderManager::PrerenderManagerMode PrerenderManager::GetMode() {
   return mode_;
 }
 
 // static
 void PrerenderManager::SetMode(PrerenderManagerMode mode) {
   mode_ = mode;
 }
 
@@ skipping 106 matching lines @@
     }
   }
 
   return result;
 }
 
 bool PrerenderManager::HasRecentlyBeenNavigatedTo(Origin origin,
                                                   const GURL& url) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-  CleanUpOldNavigations();
+  CleanUpOldNavigations(&navigations_, base::TimeDelta::FromMilliseconds(
+                                           kNavigationRecordWindowMs));
   for (auto it = navigations_.rbegin(); it != navigations_.rend(); ++it) {
     if (it->url == url) {
       base::TimeDelta delta = GetCurrentTimeTicks() - it->time;
       histograms_->RecordTimeSinceLastRecentVisit(origin, delta);
       return true;
     }
   }
 
   return false;
 }
@@ skipping 63 matching lines @@
 }
 
 void PrerenderManager::RecordFinalStatus(Origin origin,
                                          FinalStatus final_status) const {
   histograms_->RecordFinalStatus(origin, final_status);
 }
 
 void PrerenderManager::RecordNavigation(const GURL& url) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-  navigations_.push_back(NavigationRecord(url, GetCurrentTimeTicks()));
-  CleanUpOldNavigations();
+  navigations_.emplace_back(url, GetCurrentTimeTicks(), ORIGIN_NONE);
+  CleanUpOldNavigations(&navigations_, base::TimeDelta::FromMilliseconds(
+                                           kNavigationRecordWindowMs));
 }
 
 struct PrerenderManager::PrerenderData::OrderByExpiryTime {
   bool operator()(const std::unique_ptr<PrerenderData>& a,
                   const std::unique_ptr<PrerenderData>& b) const {
     return a->expiry_time() < b->expiry_time();
   }
 };
 
 PrerenderManager::PrerenderData::PrerenderData(
@@ skipping 159 matching lines @@
                                       GetExpiryTimeForNewPrerender(origin)));
   if (!prerender_contents_ptr->Init()) {
     DCHECK(active_prerenders_.end() ==
            FindIteratorForPrerenderContents(prerender_contents_ptr));
     return nullptr;
   }
 
   histograms_->RecordPrerenderStarted(origin);
   DCHECK(!prerender_contents_ptr->prerendering_has_started());
 
+  if (prerender_contents_ptr->prerender_mode() == PREFETCH_ONLY)
+    prefetches_.emplace_back(url, GetCurrentTimeTicks(), origin);
+
   std::unique_ptr<PrerenderHandle> prerender_handle =
       base::WrapUnique(new PrerenderHandle(active_prerenders_.back().get()));
   SortActivePrerenders();
 
   last_prerender_start_time_ = GetCurrentTimeTicks();
 
   gfx::Rect contents_bounds =
       bounds.IsEmpty() ? config_.default_tab_bounds : bounds;
 
   prerender_contents_ptr->StartPrerendering(contents_bounds,
@@ skipping 152 matching lines @@
 
 void PrerenderManager::DeleteOldWebContents() {
   for (WebContents* web_contents : old_web_contents_list_) {
     // TODO(dominich): should we use Instant Unload Handler here?
     // Or should |old_web_contents_list_| contain unique_ptrs?
     delete web_contents;
   }
   old_web_contents_list_.clear();
 }
 
-void PrerenderManager::CleanUpOldNavigations() {
+void PrerenderManager::CleanUpOldNavigations(
+    std::vector<NavigationRecord>* navigations,
+    base::TimeDelta max_age) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   // Cutoff. Navigations before this cutoff can be discarded.
-  base::TimeTicks cutoff = GetCurrentTimeTicks() -
-      base::TimeDelta::FromMilliseconds(kNavigationRecordWindowMs);
-  auto it = navigations_.begin();
-  for (; it != navigations_.end(); ++it) {
+  base::TimeTicks cutoff = GetCurrentTimeTicks() - max_age;
+  auto it = navigations->begin();
+  for (; it != navigations->end(); ++it) {
     if (it->time > cutoff)
       break;
   }
-  navigations_.erase(navigations_.begin(), it);
+  navigations->erase(navigations->begin(), it);
 }
 
 void PrerenderManager::ScheduleDeleteOldWebContents(
     std::unique_ptr<WebContents> tab,
     OnCloseWebContentsDeleter* deleter) {
   old_web_contents_list_.push_back(tab.release());
   PostCleanupTask();
 
   if (!deleter)
     return;
@@ skipping 177 matching lines @@
   DCHECK_EQ(1u, erased);
 }
 
 void PrerenderManager::SetPrerenderContentsFactoryForTest(
     PrerenderContents::Factory* prerender_contents_factory) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   prerender_contents_factory_.reset(prerender_contents_factory);
 }
 
 }  // namespace prerender