Add History.TopHostsVisitsByRank UMA metric.

components/history/core/browser/history_backend.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 "components/history/core/browser/history_backend.h"
 
 #include <algorithm>
 #include <functional>
 #include <list>
 #include <map>
@@ skipping 19 matching lines @@
 #include "components/history/core/browser/history_backend_observer.h"
 #include "components/history/core/browser/history_client.h"
 #include "components/history/core/browser/history_constants.h"
 #include "components/history/core/browser/history_database.h"
 #include "components/history/core/browser/history_database_params.h"
 #include "components/history/core/browser/history_db_task.h"
 #include "components/history/core/browser/in_memory_history_backend.h"
 #include "components/history/core/browser/keyword_search_term.h"
 #include "components/history/core/browser/page_usage_data.h"
 #include "components/history/core/browser/typed_url_syncable_service.h"
+#include "components/history/core/browser/url_utils.h"
 #include "components/history/core/browser/visit_filter.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
 #include "sql/error_delegate_util.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "url/gurl.h"
 #include "url/url_constants.h"
 
 #if defined(OS_IOS)
 #include "base/ios/scoped_critical_action.h"
@@ skipping 32 matching lines @@
 const int kFaviconRefetchDays = 7;
 
 // The maximum number of items we'll allow in the redirect list before
 // deleting some.
 const int kMaxRedirectCount = 32;
 
 // The number of days old a history entry can be before it is considered "old"
 // and is deleted.
 const int kExpireDaysThreshold = 90;
 
+const int kMaxTopHostsForMetrics = 50;
+
 // Converts from PageUsageData to MostVisitedURL. |redirects| is a
 // list of redirects for this URL. Empty list means no redirects.
 MostVisitedURL MakeMostVisitedURL(const PageUsageData& page_data,
                                   const RedirectList& redirects) {
   MostVisitedURL mv;
   mv.url = page_data.GetURL();
   mv.title = page_data.GetTitle();
   if (redirects.empty()) {
     // Redirects must contain at least the target url.
     mv.redirects.push_back(mv.url);
@@ skipping 307 matching lines @@
                                    ? end_ts - visit_row.visit_time
                                    : TimeDelta::FromMicroseconds(0);
     db_->UpdateVisitRow(visit_row);
   }
 }
 
 TopHostsList HistoryBackend::TopHosts(int num_hosts) const {
   if (!db_)
     return TopHostsList();
 
-  return db_->TopHosts(num_hosts);
+  auto top_hosts = db_->TopHosts(num_hosts);
+
+  host_ranks_.clear();
+  int i = 0;
+  for (const auto& host_count : top_hosts)
+    host_ranks_[host_count.first] = ++i;
+  return top_hosts;
 }
 
 void HistoryBackend::AddPage(const HistoryAddPageArgs& request) {
   if (!db_)
     return;
 
   // Will be filled with the URL ID and the visit ID of the last addition.
   std::pair<URLID, VisitID> last_ids(
       0, tracker_.GetLastVisit(request.context_id, request.nav_entry_id,
                                request.referrer));
@@ skipping 288 matching lines @@
     db_.reset();
     // Forget the first recorded time since the database is closed.
     first_recorded_time_ = base::Time();
   }
   if (thumbnail_db_) {
     thumbnail_db_->CommitTransaction();
     thumbnail_db_.reset();
   }
 }
 
+void HistoryBackend::RecordTopHostsMetrics(const GURL& url) {
+  auto it = host_ranks_.find(HostForTopHosts(url));
+  int host_rank =
+      it != host_ranks_.end() ? it->second : (kMaxTopHostsForMetrics + 1);
+
+  UMA_HISTOGRAM_ENUMERATION("History.TopHostsVisitsByRank", host_rank,
+                            kMaxTopHostsForMetrics + 2);
+}
+
 std::pair<URLID, VisitID> HistoryBackend::AddPageVisit(
     const GURL& url,
     Time time,
     VisitID referring_visit,
     ui::PageTransition transition,
     VisitSource visit_source) {
   // Top-level frame navigations are visible, everything else is hidden
   bool new_hidden = !ui::PageTransitionIsMainFrame(transition);
 
   // NOTE: This code must stay in sync with
   // ExpireHistoryBackend::ExpireURLsForVisits().
   int typed_increment = 0;
   ui::PageTransition transition_type =
       ui::PageTransitionStripQualifier(transition);
   if (ui::PageTransitionIsNewNavigation(transition) &&
       ((transition_type == ui::PAGE_TRANSITION_TYPED &&
         !ui::PageTransitionIsRedirect(transition)) ||
        transition_type == ui::PAGE_TRANSITION_KEYWORD_GENERATED))
     typed_increment = 1;
 
+  if (!host_ranks_.empty() && visit_source == SOURCE_BROWSED &&
+      (transition & ui::PAGE_TRANSITION_CHAIN_END)) {
+    RecordTopHostsMetrics(url);
+  }
+
   // See if this URL is already in the DB.
   URLRow url_info(url);
   URLID url_id = db_->GetRowForURL(url, &url_info);
   if (url_id) {
     // Update of an existing row.
     if (ui::PageTransitionStripQualifier(transition) !=
         ui::PAGE_TRANSITION_RELOAD)
       url_info.set_visit_count(url_info.visit_count() + 1);
     if (typed_increment)
       url_info.set_typed_count(url_info.typed_count() + typed_increment);
@@ skipping 1892 matching lines @@
   return true;
 }
 
 HistoryClient* HistoryBackend::GetHistoryClient() {
   if (history_client_)
     history_client_->BlockUntilBookmarksLoaded();
   return history_client_;
 }
 
 }  // namespace history