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..284a9210a628ffda248188aeff3f90718469ea1f 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/synchronization/lock.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
+#include "content/browser/renderer_host/resource_dispatcher_host.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 {
+class PrerenderTracker : public ResourceDispatcherHost::Observer {
  public:
-  // Returns the PrerenderTracker singleton.
-  static PrerenderTracker* GetInstance();
+  PrerenderTracker();
+  virtual ~PrerenderTracker();
 
   // Attempts to set the status of the specified RenderViewHost to
   // FINAL_STATUS_USED.  Returns true on success.  Returns false if it has
@@ -53,18 +52,22 @@ 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;
 
+  // ResourceDispatcherHost::Observer implementation.
+  virtual bool ShouldBeginRequest(
+      int child_id, int route_id,
+      const ResourceHostMsg_Request& request_data,
+      const content::ResourceContext& resource_context,
+      const GURL& referrer) OVERRIDE;
+
+  virtual void MutateLoadFlags(int child_id, int route_id,
+                               int* load_flags) OVERRIDE;
+
  protected:
   friend class PrerenderContents;
 
@@ -85,7 +88,13 @@ class PrerenderTracker {
   void OnPrerenderingFinished(int child_id, int route_id);
 
  private:
-  friend struct DefaultSingletonTraits<PrerenderTracker>;
+  struct RenderViewInfo {
+    explicit RenderViewInfo(PrerenderManager* prerender_manager);
+    ~RenderViewInfo();
+
+    FinalStatus final_status;
+    base::WeakPtr<PrerenderManager> prerender_manager;
+  };
 
   typedef std::pair<int, int> ChildRouteIdPair;
 
@@ -94,9 +103,6 @@ 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,
@@ -110,6 +116,11 @@ class PrerenderTracker {
   void AddPrerenderOnIOThread(const ChildRouteIdPair& child_route_id_pair);
   void RemovePrerenderOnIOThread(const ChildRouteIdPair& child_route_id_pair);
 
+  // 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;
+
   // Tasks posted to the IO Thread to call the above functions.
   static void AddPrerenderOnIOThreadTask(
       const ChildRouteIdPair& child_route_id_pair);