Monitor VideoResourceUpdater reusing destructed resource in Debug mode.

cc/resources/video_resource_updater.h

 // Copyright 2013 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 CC_RESOURCES_VIDEO_RESOURCE_UPDATER_H_
 #define CC_RESOURCES_VIDEO_RESOURCE_UPDATER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 81 matching lines @@
     ResourceFormat resource_format;
     gpu::Mailbox mailbox;
     // The balance between the number of times this resource has been returned
     // from CreateForSoftwarePlanes vs released in RecycleResource.
     int ref_count;
     // These last three members will be used for identifying the data stored in
     // this resource, and uniquely identifies a media::VideoFrame plane. The
     // 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;
 
     PlaneResource(unsigned resource_id,
                   const gfx::Size& resource_size,
                   ResourceFormat resource_format,
                   gpu::Mailbox mailbox);
     PlaneResource(const PlaneResource& other);
   };
 
@@ skipping 25 matching lines @@
   static void RecycleResource(base::WeakPtr<VideoResourceUpdater> updater,
                               unsigned resource_id,
                               const gpu::SyncToken& sync_token,
                               bool lost_resource,
                               BlockingTaskRunner* main_thread_task_runner);
   static void ReturnTexture(base::WeakPtr<VideoResourceUpdater> updater,
                             const scoped_refptr<media::VideoFrame>& video_frame,
                             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_;
   scoped_ptr<media::SkCanvasVideoRenderer> video_renderer_;
   std::vector<uint8_t> upload_pixels_;
 
   // Recycle resources so that we can reduce the number of allocations and
   // data transfers.
   ResourceList all_resources_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoResourceUpdater);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_VIDEO_RESOURCE_UPDATER_H_