Monitor VideoResourceUpdater reusing destructed resource in Debug mode.

cc/resources/video_resource_updater.h

Index: cc/resources/video_resource_updater.h
diff --git a/cc/resources/video_resource_updater.h b/cc/resources/video_resource_updater.h
index 1307be9e5416a4507b9d383581bc96f40ff40e98..16d0c0a901a8da12c20e03bde5214c7cb9238e19 100644
--- a/cc/resources/video_resource_updater.h
+++ b/cc/resources/video_resource_updater.h
@@ -99,6 +99,11 @@ class CC_EXPORT VideoResourceUpdater
     // frame pointer will only be used for pointer comparison, i.e. the
     // underlying data will not be accessed.
     const void* frame_ptr;
+#if !defined(NDEBUG)
+    // This is marked true when the orginal VideoFrame is destructed. It is used
+    // to detect the reuse of the destructed resource (in Debug mode only).

[miu, 2016/03/09 01:59:49]

Instead of "It is used to detect the reuse of the destructed resource" this
should be: "It is used to detect clients that are not setting the VideoFrame's
timestamp field correctly, as required. The memory allocator can and will re-use
the same pointer for new VideoFrame instances, so a destruction observer is used
to detect that."

[xjz, 2016/03/10 01:51:44]

Done.

+    bool destructed;
+#endif
     size_t plane_index;
     base::TimeDelta timestamp;
 
@@ -144,6 +149,12 @@ class CC_EXPORT VideoResourceUpdater
                             const gpu::SyncToken& sync_token,
                             bool lost_resource,
                             BlockingTaskRunner* main_thread_task_runner);
+#if !defined(NDEBUG)
+  // Mark the |destructed| as true when the orginal VideoFrame is destructed.
+  static void MarkOldResource(base::WeakPtr<VideoResourceUpdater> updater,
+                              const void* video_frame_ptr,
+                              base::TimeDelta timestamp);
+#endif
 
   ContextProvider* context_provider_;
   ResourceProvider* resource_provider_;