Remove a chrome dependency by removing Prerender from ResourceDispatcherHost.

chrome/browser/prerender/prerender_tracker.h

Index: chrome/browser/prerender/prerender_tracker.h
diff --git a/chrome/browser/prerender/prerender_tracker.h b/chrome/browser/prerender/prerender_tracker.h
index f2630520c12ce1359013f12e3d4a86fd085ee46c..911b3bf72a292ef0854ceef92e68b8a7d86ca6ae 100644
--- a/chrome/browser/prerender/prerender_tracker.h
+++ b/chrome/browser/prerender/prerender_tracker.h
@@ -9,22 +9,21 @@
 #include <map>
 #include <set>
 
-#include "base/memory/singleton.h"
+#include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
 
 namespace prerender {
 
 class PrerenderManager;
-struct RenderViewInfo;
 
 // PrerenderTracker is responsible for keeping track of all prerendering
 // RenderViews and their statuses.  Its list is guaranteed to be up to date
 // and can be modified on any thread.
 class PrerenderTracker {
  public:
-  // Returns the PrerenderTracker singleton.
-  static PrerenderTracker* GetInstance();
+  PrerenderTracker();
+  ~PrerenderTracker();
 
   // Attempts to set the status of the specified RenderViewHost to
   // FINAL_STATUS_USED.  Returns true on success.  Returns false if it has
@@ -53,27 +52,20 @@ class PrerenderTracker {
   bool TryCancelOnIOThread(int child_id, int route_id,
                            FinalStatus final_status);
 
-  // Returns whether or not a RenderView is prerendering.  Can only be called on
-  // the IO thread.  Does not acquire a lock, so may claim a RenderView that has
-  // been displayed or destroyed is still prerendering.
-  // TODO(mmenke):  Remove external use of this method and make it private.
-  bool IsPrerenderingOnIOThread(int child_id, int route_id) const;
-
   // Gets the FinalStatus of the specified prerendered RenderView.  Returns
   // |true| and sets |final_status| to the status of the RenderView if it
   // is found, returns false otherwise.
   bool GetFinalStatus(int child_id, int route_id,
                       FinalStatus* final_status) const;
 
+  // Returns whether or not a RenderView is prerendering.  Can only be called on
+  // the IO thread.  Does not acquire a lock, so may claim a RenderView that has
+  // been displayed or destroyed is still prerendering.
+  bool IsPrerenderingOnIOThread(int child_id, int route_id) const;
+
  protected:
   friend class PrerenderContents;
 
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerUsed);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelled);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledOnIO);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledFast);
-  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerMultiple);
-
   // Must be called when a RenderView starts prerendering, before the first
   // navigation starts to avoid any races.
   void OnPrerenderingStarted(int child_id, int route_id,
@@ -85,7 +77,20 @@ class PrerenderTracker {
   void OnPrerenderingFinished(int child_id, int route_id);
 
  private:
-  friend struct DefaultSingletonTraits<PrerenderTracker>;
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerNull);
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerUsed);
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelled);
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledOnIO);
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledFast);
+  FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerMultiple);
+
+  struct RenderViewInfo {
+    explicit RenderViewInfo(PrerenderManager* prerender_manager);
+    ~RenderViewInfo();
+
+    FinalStatus final_status;
+    base::WeakPtr<PrerenderManager> prerender_manager;
+  };
 
   typedef std::pair<int, int> ChildRouteIdPair;
 
@@ -94,9 +99,6 @@ class PrerenderTracker {
   // Set of child/route id pairs that may be prerendering.
   typedef std::set<ChildRouteIdPair> PossiblyPrerenderingChildRouteIdPairs;
 
-  PrerenderTracker();
-  ~PrerenderTracker();
-
   // Attempts to set the FinalStatus of the specified RenderView to
   // |final_status|.  If the FinalStatus of the RenderView has already been
   // set, does nothing.  Returns the resulting FinalStatus of that RenderView,