Add code to keep track of what fraction of pageviews are top sites.

chrome/browser/prerender/prerender_manager.cc

Index: chrome/browser/prerender/prerender_manager.cc
===================================================================
--- chrome/browser/prerender/prerender_manager.cc	(revision 98138)
+++ chrome/browser/prerender/prerender_manager.cc	(working copy)
@@ -15,6 +15,7 @@
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
+#include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/prerender/prerender_condition.h"
 #include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
@@ -26,15 +27,19 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper_delegate.h"
+#include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/render_messages.h"
 #include "content/browser/browser_thread.h"
+#include "content/browser/cancelable_request.h"
 #include "content/browser/renderer_host/render_process_host.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/resource_dispatcher_host.h"
 #include "content/browser/tab_contents/render_view_host_manager.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_delegate.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
 #include "content/common/notification_service.h"
 
 namespace prerender {
@@ -165,6 +170,63 @@
   Origin origin_;
 };
 
+class PrerenderManager::MostVisitedSites : public NotificationObserver {
+ public:
+  explicit MostVisitedSites(Profile* profile) :
+      profile_(profile) {
+    history::TopSites* ts = GetTopSites();
+    if (ts) {
+      registrar_.Add(this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
+                     Source<history::TopSites>(ts));
+    }
+
+    UpdateMostVisited();
+  }
+
+  void UpdateMostVisited() {
+    history::TopSites* ts = GetTopSites();
+    if (ts) {
+      ts->GetMostVisitedURLs(
+          &topsites_consumer_,
+          NewCallback(this,
+                      &prerender::PrerenderManager::MostVisitedSites::
+                      OnMostVisitedURLsAvailable));
+    }
+  }
+
+  void OnMostVisitedURLsAvailable(const history::MostVisitedURLList& data) {
+    urls_.clear();
+    for (int i = 0; i < static_cast<int>(data.size()); i++)
+      urls_.insert(data[i].url);
+  }
+
+  void Observe(int type,
+               const NotificationSource& source,
+               const NotificationDetails& details) {
+    DCHECK_EQ(type, chrome::NOTIFICATION_TOP_SITES_CHANGED);
+    UpdateMostVisited();
+  }
+
+  bool IsTopSite(const GURL& url) const {
+    return (urls_.count(url) > 0);
+  }
+
+ private:
+  history::TopSites* GetTopSites() const {
+    if (profile_)
+      return profile_->GetTopSites();
+    return NULL;
+  }
+  CancelableRequestConsumer topsites_consumer_;
+  Profile* profile_;
+  NotificationRegistrar registrar_;
+  std::set<GURL> urls_;
+};
+
+bool PrerenderManager::IsTopSite(const GURL& url) const {
+  return most_visited_->IsTopSite(url);
+}
+
 PrerenderManager::PrerenderManager(Profile* profile,
                                    PrerenderTracker* prerender_tracker)
     : enabled_(true),
@@ -175,7 +237,8 @@
           base::TimeDelta::FromMilliseconds(kMinTimeBetweenPrerendersMs)),
       runnable_method_factory_(this),
       prerender_history_(new PrerenderHistory(kHistoryLength)),
-      histograms_(new PrerenderHistograms()) {
+      histograms_(new PrerenderHistograms()),
+      most_visited_(new MostVisitedSites(profile)) {
   // There are some assumptions that the PrerenderManager is on the UI thread.
   // Any other checks simply make sure that the PrerenderManager is accessed on
   // the same thread that it was created on.