Send hardware video frames with mailboxes.

media/base/video_frame.h

Index: media/base/video_frame.h
diff --git a/media/base/video_frame.h b/media/base/video_frame.h
index 6cd5a0f7f7ccd7af2b49eb0c57c3341409c11c65..bfde2ef8b812c724acc8b08e142e667a4b186f6e 100644
--- a/media/base/video_frame.h
+++ b/media/base/video_frame.h
@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/md5.h"
+#include "gpu/command_buffer/common/mailbox.h"
 #include "media/base/buffers.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
@@ -51,6 +52,37 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
     YV12A = 14,  // 20bpp YUVA planar 1x1 Y, 2x2 VU, 1x1 A samples.
   };
 
+  // This class calls the TextureNoLongerNeededCallback when the last reference
+  // on the class is destroyed. The VideoFrame holds a reference to the mailbox
+  // but anyone else who queries the mailbox should also hold a reference while
+  // it is uses the mailbox, to ensure it remains valid. When finished with the
+  // mailbox, call Return() with a new sync point, to ensure the mailbox remains
+  // valid for the issued commands.
+  class MEDIA_EXPORT MailboxHolder
+      : public base::RefCountedThreadSafe<MailboxHolder> {
+   public:
+    typedef base::Callback<void(uint32 sync_point)>
+        TextureNoLongerNeededCallback;
+
+    MailboxHolder(const gpu::Mailbox& mailbox,
+                  unsigned sync_point,
+                  const TextureNoLongerNeededCallback& release_callback);
+
+    const gpu::Mailbox& mailbox() const { return mailbox_; }
+    unsigned sync_point() const { return sync_point_; }
+
+    void Return(unsigned sync_point) { sync_point_ = sync_point; }
+
+   private:
+    friend class base::RefCountedThreadSafe<MailboxHolder>;
+    ~MailboxHolder();
+
+    gpu::Mailbox mailbox_;
+    unsigned sync_point_;
+    TextureNoLongerNeededCallback release_callback_;
+  };
+
+
   // Creates a new frame in system memory with given parameters. Buffers for
   // the frame are allocated but not initialized.
   // |coded_size| is the width and height of the frame data in pixels.
@@ -87,7 +119,7 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
   // |read_pixels_cb| may be used to do (slow!) readbacks from the
   // texture to main memory.
   static scoped_refptr<VideoFrame> WrapNativeTexture(
-      uint32 texture_id,
+      const scoped_refptr<MailboxHolder>& mailbox_holder,
       uint32 texture_target,
       const gfx::Size& coded_size,
       const gfx::Rect& visible_rect,
@@ -158,9 +190,10 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
   // VideoFrame object and must not be freed by the caller.
   uint8* data(size_t plane) const;
 
-  // Returns the ID of the native texture wrapped by this frame.  Only valid to
-  // call if this is a NATIVE_TEXTURE frame.
-  uint32 texture_id() const;
+  // Returns the mailbox of the native texture wrapped by this frame. Only
+  // valid to call if this is a NATIVE_TEXTURE frame. Before using the
+  // mailbox, the caller must wait for the included sync point.
+  const scoped_refptr<MailboxHolder>& texture_mailbox() const;
 
   // Returns the texture target. Only valid for NATIVE_TEXTURE frames.
   uint32 texture_target() const;
@@ -217,8 +250,8 @@ class MEDIA_EXPORT VideoFrame : public base::RefCountedThreadSafe<VideoFrame> {
   // Array of data pointers to each plane.
   uint8* data_[kMaxPlanes];
 
-  // Native texture ID, if this is a NATIVE_TEXTURE frame.
-  uint32 texture_id_;
+  // Native texture mailbox, if this is a NATIVE_TEXTURE frame.
+  scoped_refptr<MailboxHolder> texture_mailbox_holder_;
   uint32 texture_target_;
   ReadPixelsCB read_pixels_cb_;