Add observer interface to PrerenderContents.

chrome/browser/prerender/prerender_tracker.h

 // 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.
 
 #ifndef CHROME_BROWSER_PRERENDER_PRERENDER_TRACKER_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_TRACKER_H_
 
 #include <map>
 #include <set>
+#include <utility>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/non_thread_safe.h"
+#include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/prerender/prerender_final_status.h"
 #include "googleurl/src/gurl.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 base::NonThreadSafe,
+                         public PrerenderContents::Observer {
  public:
   PrerenderTracker();
-  ~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
   // already been cancelled for any reason or is no longer prerendering.
   // Can only be called only on the IO thread.  This method will not call
-  // PrerenderContents::set_final_status() on the corresponding
-  // PrerenderContents.
+  // PrerenderContents::SetFinalStatus() on the corresponding PrerenderContents.
   //
   // If it returns true, all subsequent calls to TryCancel and TryUse for the
   // RenderView will return false.
   bool TryUse(int child_id, int route_id);
 
   // Attempts to cancel prerendering by the specified RenderView, setting the
   // FinalStatus to |final_status|.  Returns true if the specified prerender has
   // been cancelled, either as a result of this call or for any other reason.
   // If the call results in cancelling a PrerenderContents, a task to destroy
   // it is also posted to the UI thread.
@@ skipping 27 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledOnIO);
   FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerCancelledFast);
   FRIEND_TEST_ALL_PREFIXES(PrerenderTrackerTest, PrerenderTrackerMultiple);
 
   typedef std::pair<int, int> ChildRouteIdPair;
   // Map of child/route id pairs to final statuses.
   typedef std::map<ChildRouteIdPair, RenderViewInfo> FinalStatusMap;
   // Set of child/route id pairs that may be prerendering.
   typedef std::set<ChildRouteIdPair> PossiblyPrerenderingChildRouteIdPairs;
 
-  // 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,
-                             PrerenderManager* prerender_manager);
-
-  // Must be called when a RenderView stops prerendering, either because the
-  // RenderView was used or prerendering was cancelled and it is being
-  // destroyed.
-  void OnPrerenderingFinished(int child_id, int route_id);
+  // From PrerenderContents::Observer:
+  virtual void OnPrerenderStart(PrerenderContents* prerender_contents) OVERRIDE;
+  virtual void OnPrerenderStop(PrerenderContents* prerender_contents) OVERRIDE;
 
   // Attempts to set the FinalStatus of the specified RenderView to
   // |desired_final_status|.  If non-NULL, |actual_final_status| is set to the
   // FinalStatus of the RenderView.
   //
   // If the FinalStatus of the RenderView is successfully set, returns true and
   // sets |actual_final_status| to |desired_final_status|.
   //
   // If the FinalStatus of the RenderView was already set, returns false and
   // sets |actual_final_status| to the actual FinalStatus of the RenderView.
@@ skipping 28 matching lines @@
   // the IO thread.  May contain entries that have since been displayed.  Only
   // used to prevent locking when not needed.
   PossiblyPrerenderingChildRouteIdPairs possibly_prerendering_io_thread_set_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderTracker);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_TRACKER_H_