Add media::VideoEncodeAccelerator with WebRTC integration

content/common/gpu/gpu_messages.h

Index: content/common/gpu/gpu_messages.h
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 5749c371c1b7cfe1c492ffbe3f1548e65f395903..e9f379d9497f4d076c168e8e35483f6771993120 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -23,7 +23,9 @@
 #include "gpu/ipc/gpu_command_buffer_traits.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
+#include "media/base/video_frame.h"
 #include "media/video/video_decode_accelerator.h"
+#include "media/video/video_encode_accelerator.h"
 #include "ui/base/latency_info.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
@@ -217,6 +219,10 @@ IPC_STRUCT_TRAITS_BEGIN(content::GpuRenderingStats)
   IPC_STRUCT_TRAITS_MEMBER(total_processing_commands_time)
 IPC_STRUCT_TRAITS_END()
 
+IPC_ENUM_TRAITS(media::VideoFrame::Format)
+
+IPC_ENUM_TRAITS(media::VideoEncodeAccelerator::Error)
+
 //------------------------------------------------------------------------------
 // GPU Messages
 // These are messages from the browser to the GPU process.
@@ -447,6 +453,12 @@ IPC_MESSAGE_CONTROL1(GpuChannelMsg_GenerateMailboxNamesAsync,
 IPC_MESSAGE_CONTROL1(GpuChannelMsg_GenerateMailboxNamesReply,
                      std::vector<gpu::Mailbox> /* mailbox_names */)
 
+// Create a new GPU-accelerated video encoder.
+IPC_SYNC_MESSAGE_CONTROL0_1(GpuChannelMsg_CreateVideoEncoder,
+                            int32 /* route_id */)
+
+IPC_MESSAGE_CONTROL1(GpuChannelMsg_DestroyVideoEncoder, int32 /* route_id */)
+
 #if defined(OS_ANDROID)
 // Register the StreamTextureProxy class with the GPU process, so that
 // the renderer process will get notified whenever a frame becomes available.
@@ -690,3 +702,53 @@ IPC_MESSAGE_ROUTED0(AcceleratedVideoDecoderHostMsg_ResetDone)
 // Video decoder has encountered an error.
 IPC_MESSAGE_ROUTED1(AcceleratedVideoDecoderHostMsg_ErrorNotification,
                     uint32) /* Error ID */
+
+//------------------------------------------------------------------------------
+// Accelerated Video Encoder Messages
+// These messages are sent from the Renderer process to GPU process.
+
+// Initialize the accelerated encoder.
+IPC_MESSAGE_ROUTED4(AcceleratedVideoEncoderMsg_Initialize,
+                    media::VideoFrame::Format /* input_format */,
+                    gfx::Size /* input_visible_size */,
+                    media::VideoCodecProfile /* output_profile */,
+                    int32 /* initial_bitrate */)
+
+// Queue a input buffer to the encoder to encode.
+IPC_MESSAGE_ROUTED4(AcceleratedVideoEncoderMsg_Encode,
+                    int32 /* frame_id */,
+                    base::SharedMemoryHandle /* buffer_handle */,
+                    uint32 /* buffer_size */,
+                    bool /* force_keyframe */)
+
+// Queue a buffer to the encoder for use in returning output.
+IPC_MESSAGE_ROUTED3(AcceleratedVideoEncoderMsg_UseOutputBitstreamBuffer,
+                    int32 /* buffer_id */,
+                    base::SharedMemoryHandle /* buffer_handle */,
+                    uint32 /* buffer_size */)
+
+// Request a runtime encoding parameter change.
+IPC_MESSAGE_ROUTED1(AcceleratedVideoEncoderMsg_RequestEncodingParameterChange,
+                    int32 /* bitrate */)
+
+//------------------------------------------------------------------------------
+// Accelerated Video Encoder Host Messages
+// These messages are sent from GPU process to Renderer process.
+
+IPC_MESSAGE_ROUTED0(AcceleratedVideoEncoderHostMsg_NotifyInitializeDone)
+
+IPC_MESSAGE_ROUTED3(AcceleratedVideoEncoderHostMsg_RequireBitstreamBuffers,
+                    int /* input_count */,
+                    gfx::Size /* input_coded_size */,
+                    uint32 /* output_buffer_size */)
+
+IPC_MESSAGE_ROUTED1(AcceleratedVideoEncoderHostMsg_NotifyEncodeDone,

[Ami GONE FROM CHROMIUM, 2013/08/05 18:44:38]

If this remains outside the VEA::Client interface then it should be doco'd here.
 I believe this means something like "Done with |frame_id|, feel free to use it
for other purposes." and not something like "The bitstreambuffer representing
the picture from |frame_id| has been emitted using BBR."

I suspect, though, that this should actually be part of the VEA::Client API,
with a comment like the above present _there_, and then no change in this file.

[sheu, 2013/08/06 06:16:36]

As part of the move to media::VideoFrame: since VideoFrame has its own
destructor callback, the VEA::Client API does not need an explicit EncodeDone(),
but we still need to communicate that across IPC.

I'll add notes here documenting this wrinkle.

Actually I'll just add the boilerplate documentation to the rest of the IPCs
too.

+                    int32 /* frame_id */)
+
+IPC_MESSAGE_ROUTED3(AcceleratedVideoEncoderHostMsg_BitstreamBufferReady,
+                    int32 /* bitstream_buffer_id */,
+                    uint32 /* payload_size */,
+                    bool /* key_frame */)
+
+IPC_MESSAGE_ROUTED1(AcceleratedVideoEncoderHostMsg_NotifyError,
+                    media::VideoEncodeAccelerator::Error /* error */)