media: Create Mojo StructTraits for VideoFrame

media/mojo/interfaces/media_types.mojom

 // Copyright 2014 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.
 
 module media.mojom;
 
 import "gpu/ipc/common/mailbox_holder.mojom";
 import "mojo/common/time.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
@@ skipping 229 matching lines @@
   int32 y_stride;
   int32 u_stride;
   int32 v_stride;
   uint64 y_offset;
   uint64 u_offset;
   uint64 v_offset;
 };
 
 // This defines video frame data stored in texture mailboxes.
 struct MailboxVideoFrameData {
-  array<gpu.mojom.MailboxHolder> mailbox_holder;
+  // Size must be kept in sync with media::VideoFrame::kMaxPlanes.

[dcheng, 2017/06/05 20:33:01]

Ideally, we'd just define the constant in mojom, but I'm guessing we don't (or
can't) currently depend on mojo in that file.

[sandersd (OOO until July 31), 2017/06/05 20:46:13]

That's correct; //media is not allowed to depend on //media/mojo.

+  array<gpu.mojom.MailboxHolder, 4> mailbox_holder;
 };
 
 struct PipelineStatistics {
   uint64 audio_bytes_decoded;
   uint64 video_bytes_decoded;
   uint32 video_frames_decoded;
   uint32 video_frames_dropped;
   int64 audio_memory_usage;
   int64 video_memory_usage;
 };