B0;136;0cRe-enable TopSites in PrerenderManager, this time duplicating the invariant

observed in NTP (browser must have started).
R=sky, cbentzel
Review URL: http://codereview.chromium.org/7828023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@99741 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/history/top_sites.cc

@@ -164,6 +164,8 @@ TopSites::TopSites(Profile* profile)
       profile_->GetPrefs()->GetDictionary(prefs::kNTPMostVisitedURLsBlacklist);
   pinned_urls_ =
       profile_->GetPrefs()->GetDictionary(prefs::kNTPMostVisitedPinnedURLs);
+  DCHECK(blacklist_ != NULL);
+  DCHECK(pinned_urls_ != NULL);
 }
 
 void TopSites::Init(const FilePath& db_name) {

chrome/browser/prerender/prerender_manager.cc

@@ -173,19 +173,6 @@ class PrerenderManager::MostVisitedSites : public NotificationObserver {
  public:
   explicit MostVisitedSites(Profile* profile) :
       profile_(profile) {
-    // If TopSites is already loaded, we will want to use it right away.
-    // Otherwise, wait for three seconds to avoid race conditions.
-    // This is a hack to ensure unit tests don't fail.
-    // See http://crbug.com/94654
-    if (profile && profile->GetTopSitesWithoutCreating()) {
-      Init();
-    } else {
-      timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(3), this,
-                   &prerender::PrerenderManager::MostVisitedSites::Init);
-    }
-  }
-
-  void Init() {
     history::TopSites* top_sites = GetTopSites();
     if (top_sites) {
       registrar_.Add(this, chrome::NOTIFICATION_TOP_SITES_CHANGED,
@@ -234,11 +221,12 @@ class PrerenderManager::MostVisitedSites : public NotificationObserver {
   Profile* profile_;
   NotificationRegistrar registrar_;
   std::set<GURL> urls_;
-  base::OneShotTimer<prerender::PrerenderManager::MostVisitedSites> timer_;
 };
 
-bool PrerenderManager::IsTopSite(const GURL& url) const {
-  return most_visited_.get() && most_visited_->IsTopSite(url);
+bool PrerenderManager::IsTopSite(const GURL& url) {
+  if (!most_visited_.get())
+    most_visited_.reset(new MostVisitedSites(profile_));
+  return most_visited_->IsTopSite(url);
 }
 
 PrerenderManager::PrerenderManager(Profile* profile,

chrome/browser/prerender/prerender_manager.h

@@ -204,7 +204,7 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
   // Adds a condition. This is owned by the PrerenderManager.
   void AddCondition(const PrerenderCondition* condition);
 
-  bool IsTopSite(const GURL& url) const;
+  bool IsTopSite(const GURL& url);
 
  protected:
   // Test that needs needs access to internal functions.

chrome/browser/prerender/prerender_tab_helper.cc

@@ -310,7 +310,7 @@ void PrerenderTabHelper::MaybeLogCurrentHover(bool was_used) {
   current_hover_url_ = GURL();
 }
 
-bool PrerenderTabHelper::IsTopSite(const GURL& url) const {
+bool PrerenderTabHelper::IsTopSite(const GURL& url) {
   PrerenderManager* pm = MaybeGetPrerenderManager();
   return (pm && pm->IsTopSite(url));
 }

chrome/browser/prerender/prerender_tab_helper.h

@@ -61,7 +61,7 @@ class PrerenderTabHelper : public TabContentsObserver {
   // Also resets the hover to no hover.
   void MaybeLogCurrentHover(bool was_used);
 
-  bool IsTopSite(const GURL& url) const;
+  bool IsTopSite(const GURL& url);
 
   // TabContentsWrapper we're created for.
   TabContentsWrapper* tab_;