Implement software fallback for PPB_VideoDecoder.

content/renderer/pepper/video_decoder_proxy.cc

+// Copyright (c) 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.
+
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+#include <GLES2/gl2extchromium.h>
+
+#include "content/renderer/pepper/video_decoder_proxy.h"
+
+#include "base/bind.h"
+#include "content/public/renderer/render_thread.h"
+#include "content/renderer/pepper/pepper_video_decoder_host.h"
+#include "content/renderer/render_thread_impl.h"
+#include "gpu/command_buffer/client/gles2_implementation.h"
+#include "media/base/decoder_buffer.h"
+#include "media/filters/ffmpeg_video_decoder.h"
+#include "media/video/picture.h"
+#include "media/video/video_decode_accelerator.h"
+#include "ppapi/c/pp_errors.h"
+#include "third_party/libyuv/include/libyuv.h"
+#include "webkit/common/gpu/context_provider_web_context.h"
+
+namespace content {
+
+VideoDecoderProxy::PendingDecode::PendingDecode(
+    uint32_t decode_id,
+    const scoped_refptr<media::DecoderBuffer>& buffer)
+    : decode_id(decode_id), buffer(buffer) {
+}
+
+VideoDecoderProxy::PendingDecode::~PendingDecode() {
+}
+
+VideoDecoderProxy::PendingFrame::PendingFrame(uint32_t decode_id,
+                                              const gfx::Size& size)
+    : decode_id(decode_id),
+      size(size),
+      pixels(size.width() * size.height() * 4) {
+}
+
+VideoDecoderProxy::PendingFrame::~PendingFrame() {
+}
+
+VideoDecoderProxy::Delegate::Delegate(
+    const base::WeakPtr<VideoDecoderProxy>& proxy)
+    : proxy_(proxy), main_message_loop_(base::MessageLoopProxy::current()) {
+}
+
+VideoDecoderProxy::Delegate::~Delegate() {
+  DCHECK(pending_decodes_.empty());

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

what guarantees this?
I think you might be relying on decoder_->Stop() to fire pending ConvertFrame's,
which would keep draining pending_decodes_.  But that implies that VideoDecoder
is re-entrant this way (that you can call VD::Decode from the callback that is
invoked as a result of calling VD::Stop) which seems like a bad assumption.  I
think you need to explicitly drop pending decodes before calling VD::Stop in
Destroy.

[bbudge, 2014/06/06 02:03:45]

Done.

+}
+
+void VideoDecoderProxy::Delegate::Initialize(
+    scoped_ptr<media::VideoDecoder> decoder,
+    media::VideoDecoderConfig config) {
+  DCHECK(!decoder_);
+  decoder_.reset(decoder.release());

[dmichael (off chromium), 2014/06/05 23:00:43]

tiny nit: I think I would write this as decoder_ = decoder.Pass();
(Even though your code is good, I try to prefer Pass whenever possible, since
it's a little harder to mess up)

[bbudge, 2014/06/06 02:03:45]

This is no longer an argument.

+  decoder_->Initialize(
+      config,
+      true /* low_delay */,
+      base::Bind(&VideoDecoderProxy::Delegate::OnPipelineStatus,
+                 base::Unretained(this)));

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

I guess the only reason this isn't a UAF waiting to happen is that
VideoDecoder::Stop() is synchronous and always happens before |this| is
destroyed.  Might be worth a comment.

[bbudge, 2014/06/06 02:03:45]

Done.

+}
+
+void VideoDecoderProxy::Delegate::OnPipelineStatus(
+    media::PipelineStatus status) {
+  main_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoDecoderProxy::OnPipelineStatus, proxy_, status));
+}
+
+void VideoDecoderProxy::Delegate::ReceiveBuffer(
+    uint32_t decode_id,
+    scoped_refptr<media::DecoderBuffer> buffer) {
+  bool decoder_busy = !pending_decodes_.empty();
+  pending_decodes_.push(PendingDecode(decode_id, buffer));
+  if (!decoder_busy)

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

FWIW can drop decoder_busy if you do
if (pending_decodes_.size() > 1)
here

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

AFAICT a client that never calls Reset() can never see this decoder_busy
condition; am I missing something?

[bbudge, 2014/06/06 02:03:44]

I changed this and now call VD::GetMaxDecodeRequests() to get the max number
(apparently it's 1 for FfmpegVideoDecoder.) I maintain the count of pending
decodes and check if I can just call Decode before enqueueing.

[bbudge, 2014/06/06 02:03:45]

It happens at startup and on reset. In the steady state, you're right, since we
notify that the bitstream is done only when we've completed decoding. In
reality, we could notify much earlier when we copy into the DecoderBuffer, but
this way puts back pressure against the plugin so we don't copy their entire
stream.

+    Decode();
+}
+
+void VideoDecoderProxy::Delegate::Decode() {
+  DCHECK(!pending_decodes_.empty());
+  PendingDecode& next_decode = pending_decodes_.front();

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

const& is less surprising

[bbudge, 2014/06/06 02:03:45]

Done.

+  decoder_->Decode(next_decode.buffer,
+                   base::Bind(&VideoDecoderProxy::Delegate::ConvertFrame,
+                              base::Unretained(this),
+                              next_decode.decode_id));
+  pending_decodes_.pop();
+}
+
+void VideoDecoderProxy::Delegate::ConvertFrame(
+    uint32_t decode_id,
+    media::VideoDecoder::Status status,
+    const scoped_refptr<media::VideoFrame>& frame) {
+  scoped_ptr<PendingFrame> pending_frame(
+      new PendingFrame(decode_id, gfx::Size()));
+  if (frame) {

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

You're using frame!=NULL as a proxy for status==kOk even though you have the
status right here.  I'd use status instead.  That might make it clearer that you
need to also test for frame->end_of_stream().

[bbudge, 2014/06/06 02:03:45]

So:
if (status == kOk && frame && !frame->end_of_stream())  ?

+    pending_frame->size = frame->coded_size();
+    pending_frame->pixels.resize(frame->coded_size().width() *

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

It's strange that you do the w*h*4 calc here _and_ in the ctor and that hte ctor
is always passed a 0x0 size.

[bbudge, 2014/06/06 02:03:45]

Added a ctor to create an empty frame, and defer construction of frames until I
know the size. Done.

+                                 frame->coded_size().height() * 4);
+    // Convert the decoded frame to ARGB pixels.
+    libyuv::I420ToARGB(frame->data(media::VideoFrame::kYPlane),
+                       frame->stride(media::VideoFrame::kYPlane),
+                       frame->data(media::VideoFrame::kUPlane),
+                       frame->stride(media::VideoFrame::kUPlane),
+                       frame->data(media::VideoFrame::kVPlane),
+                       frame->stride(media::VideoFrame::kVPlane),
+                       &pending_frame->pixels.front(),
+                       frame->coded_size().width() * 4,
+                       frame->coded_size().width(),
+                       frame->coded_size().height());
+  }
+
+  main_message_loop_->PostTask(FROM_HERE,
+                               base::Bind(&VideoDecoderProxy::ReceiveFrame,
+                                          proxy_,
+                                          status,
+                                          base::Passed(&pending_frame)));
+
+  if (!pending_decodes_.empty())

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

per comment at l.78, can this arise in the absence of Reset()?
If Reset() _was_ called, shouldn't in-flight frames & buffers be dropped on the
floor instead of being drained?

[bbudge, 2014/06/06 02:03:45]

Stop() and Reset() now clear pending frames first, so this won't happen. Added a
comment where I clear.

+    Decode();
+}
+
+void VideoDecoderProxy::Delegate::Reset() {
+  decoder_->Reset(base::Bind(&VideoDecoderProxy::Delegate::OnResetComplete,

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

set some state so that decodes that arrive from now until OnResetComplete aren't
sent to the decoder?

[bbudge, 2014/06/06 02:03:44]

No decodes can arrive until Reset completes because of VideoDecoderProxy's state
checks. Also, pending_decodes_ is cleared here, so we won't kick off a Decode in
OnDecodeComplete.

+                             base::Unretained(this)));
+}
+
+void VideoDecoderProxy::Delegate::OnResetComplete() {
+  // Cancel all remaining decodes, and notify the host so it can free the shm

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

is it obvious why this shouldn't have been done in Reset()?

[bbudge, 2014/06/06 02:03:44]

No, it should be done in Reset() as you point out.

+  // buffers. We'll clear pending frames on the main thread.
+  while (!pending_decodes_.empty()) {
+    PendingDecode& next_decode = pending_decodes_.front();
+    scoped_ptr<PendingFrame> pending_frame(
+        new PendingFrame(next_decode.decode_id, gfx::Size()));
+    main_message_loop_->PostTask(FROM_HERE,
+                                 base::Bind(&VideoDecoderProxy::ReceiveFrame,
+                                            proxy_,
+                                            media::VideoDecoder::kAborted,
+                                            base::Passed(&pending_frame)));

[dmichael (off chromium), 2014/06/05 23:00:43]

Any reason you can't pass a null pointer instead of an empty frame?

[bbudge, 2014/06/06 02:03:44]

The frame has the decode_id, which is used to identify the shm buffer that is
now available.

+    pending_decodes_.pop();
+  }
+  main_message_loop_->PostTask(
+      FROM_HERE, base::Bind(&VideoDecoderProxy::OnResetComplete, proxy_));
+}
+
+void VideoDecoderProxy::Delegate::Destroy() {
+  DCHECK(decoder_);
+  decoder_->Stop();

[dmichael (off chromium), 2014/06/05 23:00:43]

Would it be safe to instead put this in the destructor, and use DeleteSoon from
VideoDecoderProxy? I'd prefer simpler destruction semantics if it would work.

[bbudge, 2014/06/06 02:03:45]

Stop can cause callbacks to run, and I'd rather not do those while we're in the
body of the destructor.

+  // By now, our owning VideoDecoderProxy has invalidated our weak_ptr to it.
+}
+
+VideoDecoderProxy::VideoDecoderProxy(PepperVideoDecoderHost* host)
+    : state_(UNINITIALIZED),
+      host_(host),
+      media_message_loop_(
+          RenderThreadImpl::current()->GetMediaThreadMessageLoopProxy()),
+      context_provider_(
+          RenderThreadImpl::current()->SharedMainThreadContextProvider()),
+      num_pending_decodes_(0),

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

the logic around this member requires that Decode() calls correspond 1:1 with
frames, but this isn't doco'd in the header.

[bbudge, 2014/06/06 02:03:44]

Done.

+      weak_ptr_factory_(this) {
+  DCHECK(host_);
+  DCHECK(media_message_loop_);
+  DCHECK(context_provider_);
+  delegate_.reset(new Delegate(weak_ptr_factory_.GetWeakPtr()));
+}
+
+VideoDecoderProxy::~VideoDecoderProxy() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(!host_);
+  // Delete any remaining video frames.
+  while (!pending_frames_.empty()) {
+    delete pending_frames_.front();
+    pending_frames_.pop();
+  }
+  // Delete any remaining textures.
+  TextureIdMap::iterator it = texture_id_map_.begin();
+  for (; it != texture_id_map_.end(); ++it)
+    DeleteTexture(it->second);
+

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

clear the map once done?

[bbudge, 2014/06/06 02:03:44]

It will be destroyed once we exit the body.

+  FlushCommandBuffer();
+}
+
+void VideoDecoderProxy::Initialize(media::VideoCodecProfile profile) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK_EQ(state_, UNINITIALIZED);
+  media::VideoCodec codec = media::kUnknownVideoCodec;
+  if (profile <= media::H264PROFILE_MAX)
+    codec = media::kCodecH264;
+  else if (profile <= media::VP8PROFILE_MAX)
+    codec = media::kCodecVP8;
+  DCHECK_NE(codec, media::kUnknownVideoCodec);
+
+  media::VideoDecoderConfig config(
+      codec,
+      profile,
+      media::VideoFrame::YV12,
+      gfx::Size(32, 24),  // Small sizes that won't fail.
+      gfx::Rect(32, 24),
+      gfx::Size(32, 24),
+      NULL /* extra_data */,

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

durr, does this really work?
e.g. does the h264 test pass on linux?

[bbudge, 2014/06/06 02:03:45]

I don't know. I'll have to try it. I have no idea what to pass in here in any
case.

+      0 /* extra_data_size */,
+      false /* decryption */);
+
+  scoped_ptr<media::VideoDecoder> decoder(
+      new media::FFmpegVideoDecoder(media_message_loop_));

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

Why not VpxVideoDecoder (for VP9) or one of the decrypting ones?
(seems like if you're gonna hard-code this here then VideoDecoderProxy is not as
generic a proxy as the name might imply; worth a class header doco)

[bbudge, 2014/06/06 02:03:45]

You're right. I moved VideoDecoder construction into the Delegate class. I plan
to add VP9 to the API and implementation in a future CL.

+
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoDecoderProxy::Delegate::Initialize,
+                 base::Unretained(delegate_.get()),
+                 base::Passed(&decoder),
+                 config));
+  state_ = DECODING;

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

shouldn't this transition only happen in the OK case of OnPipelineStatus()?

[bbudge, 2014/06/06 02:03:45]

Yep.

+}
+
+void VideoDecoderProxy::Decode(uint32_t decode_id,
+                               const uint8_t* buffer,
+                               uint32_t size) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK_EQ(state_, DECODING);
+
+  num_pending_decodes_++;
+
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoDecoderProxy::Delegate::ReceiveBuffer,
+                 base::Unretained(delegate_.get()),
+                 decode_id,
+                 media::DecoderBuffer::CopyFrom(buffer, size)));
+}
+
+void VideoDecoderProxy::AssignTextures(
+    const std::vector<uint32_t>& texture_ids) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK_EQ(state_, DECODING);
+  DCHECK(texture_ids.size());

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

DCHECK(texture_id_map_.empty());
?

[dmichael (off chromium), 2014/06/05 23:00:44]

With a "!", of course :)

[bbudge, 2014/06/06 02:03:45]

I don't think so. We AssignTextures when the video size changes, but we can't
dismiss textures until the plugin recycles them. Couldn't the plugin hang on to
an old texture indefinitely?

+  DCHECK_EQ(texture_ids.size(), pending_texture_mailboxes_.size());
+  uint32_t num_textures = static_cast<GLuint>(texture_ids.size());

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

checked_cast to avoid silent overflow

[bbudge, 2014/06/06 02:03:45]

Done.

+  std::vector<uint32_t> local_texture_ids(num_textures);
+  gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+  gles2->GenTextures(num_textures, &local_texture_ids.front());
+  for (uint32_t i = 0; i < num_textures; i++) {
+    gles2->ActiveTexture(GL_TEXTURE0);
+    gles2->BindTexture(GL_TEXTURE_2D, local_texture_ids[i]);
+    gles2->ConsumeTextureCHROMIUM(GL_TEXTURE_2D,
+                                  pending_texture_mailboxes_[i].name);
+    // Map the plugin texture id to the local texture id.
+    texture_id_map_.insert(
+        std::make_pair(texture_ids[i], local_texture_ids[i]));

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

since you're ignoring return value you may as well
texture_id_map_[texture_ids[i]] = local_texture_ids[i];

[bbudge, 2014/06/06 02:03:44]

Done.

+  }
+  pending_texture_mailboxes_.clear();
+  available_textures_.insert(
+      available_textures_.end(), texture_ids.begin(), texture_ids.end());
+  SendPictures();
+}
+
+void VideoDecoderProxy::RecycleTexture(uint32_t texture_id) {
+  DCHECK(RenderThreadImpl::current());
+  if (textures_to_dismiss_.find(texture_id) != textures_to_dismiss_.end()) {
+    DismissTexture(texture_id);
+  } else if (texture_id_map_.find(texture_id) != texture_id_map_.end()) {
+    available_textures_.push_back(texture_id);
+    SendPictures();
+  } else {
+    NOTREACHED();
+  }
+}
+
+void VideoDecoderProxy::Flush() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK_EQ(state_, DECODING);
+  state_ = FLUSHING;
+}
+
+void VideoDecoderProxy::Reset() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK_EQ(state_, DECODING);
+  state_ = RESETTING;
+  media_message_loop_->PostTask(FROM_HERE,
+                                base::Bind(&VideoDecoderProxy::Delegate::Reset,
+                                           base::Unretained(delegate_.get())));
+}
+
+void VideoDecoderProxy::Destroy() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(host_);
+  host_ = NULL;
+  // Cut the delegate loose.
+  weak_ptr_factory_.InvalidateWeakPtrs();
+  media_message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoDecoderProxy::Delegate::Destroy,
+                 base::Owned(delegate_.release())));
+
+  delete this;

[dmichael (off chromium), 2014/06/05 23:00:43]

Can we just do all this in a destructor? (aside from delete this :) )

[bbudge, 2014/06/06 02:03:44]

That's too late. There might be pending callbacks on the main message loop. I've
added some comments to make this clearer.

+}
+
+void VideoDecoderProxy::OnPipelineStatus(media::PipelineStatus status) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(host_);
+
+  int32_t result;
+  switch (status) {
+    case media::PIPELINE_OK:
+      result = PP_OK;
+      break;
+    case media::DECODER_ERROR_NOT_SUPPORTED:
+      result = PP_ERROR_NOTSUPPORTED;
+      break;
+    default:
+      result = PP_ERROR_FAILED;
+      break;
+  }
+  host_->OnInitializeComplete(result);
+}
+
+void VideoDecoderProxy::ReceiveFrame(media::VideoDecoder::Status status,
+                                     scoped_ptr<PendingFrame> frame) {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(host_);
+
+  num_pending_decodes_--;
+
+  if (frame->pixels.size()) {
+    if (texture_size_ != frame->size) {
+      // If the size has changed, all current textures must be dismissed. Add
+      // all textures to |textures_to_dismiss_| and dismiss any that aren't in
+      // use by the plugin. We dismiss the rest as they are recycled.
+      for (TextureIdMap::const_iterator it = texture_id_map_.begin();
+           it != texture_id_map_.end();
+           ++it) {
+        textures_to_dismiss_.insert(it->second);
+      }
+      for (std::vector<uint32_t>::const_iterator it =
+               available_textures_.begin();
+           it != available_textures_.end();
+           ++it) {
+        DismissTexture(*it);
+      }
+      available_textures_.clear();
+      FlushCommandBuffer();
+
+      DCHECK(pending_texture_mailboxes_.empty());
+      const uint32_t num_textures = 8;

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

o rly 8?

[bbudge, 2014/06/06 02:03:44]

Yeah, this is just a guess. It seems like 1 might cause things to slow down. I'm
open to suggestions. Is it dependent on decoder's GetMaxDecodeRequests number?

+      for (uint32_t i = 0; i < num_textures; i++)
+        pending_texture_mailboxes_.push_back(gpu::Mailbox::Generate());
+
+      host_->RequestTextures(
+          num_textures, frame->size, GL_TEXTURE_2D, pending_texture_mailboxes_);
+      texture_size_ = frame->size;
+    }
+
+    pending_frames_.push(frame.release());
+    SendPictures();
+  } else {
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

In case of error this is wrong.

[bbudge, 2014/06/06 02:03:44]

I don't see why. With VideoDecodeAccelerator we notify when we kick off the
Decode. In VDP, we defer that to exert back pressure on the plugin, but the
behavior matches that of VDA.

+  }
+
+  switch (status) {
+    case media::VideoDecoder::kOk:
+    case media::VideoDecoder::kAborted:
+    // This is not necessarily an error.
+    case media::VideoDecoder::kNotEnoughData:
+      break;
+    case media::VideoDecoder::kDecodeError:
+    case media::VideoDecoder::kDecryptError:

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

_decrypt_ error should be unreachable, right?

[bbudge, 2014/06/06 02:03:44]

Done.

+      host_->NotifyError(PP_ERROR_RESOURCE_FAILED);
+      break;
+      // No default case, to catch unhandled status values.
+  }
+}
+
+void VideoDecoderProxy::SendPictures() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(host_);
+
+  while (!pending_frames_.empty() && !available_textures_.empty()) {
+    scoped_ptr<PendingFrame> frame(pending_frames_.front());
+    pending_frames_.pop();
+
+    uint32_t texture_id = available_textures_.back();
+    available_textures_.pop_back();
+
+    uint32_t local_texture_id = texture_id_map_[texture_id];
+    gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+    gles2->ActiveTexture(GL_TEXTURE0);
+    gles2->BindTexture(GL_TEXTURE_2D, local_texture_id);
+    gles2->TexImage2D(GL_TEXTURE_2D,
+                      0,
+                      GL_RGBA,
+                      texture_size_.width(),
+                      texture_size_.height(),
+                      0,
+                      GL_RGBA,
+                      GL_UNSIGNED_BYTE,
+                      &frame->pixels.front());
+
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);
+    host_->PictureReady(media::Picture(texture_id, frame->decode_id));
+  }
+
+  FlushCommandBuffer();
+
+  if (state_ == FLUSHING && !num_pending_decodes_ && pending_frames_.empty()) {
+    state_ = DECODING;
+    host_->NotifyFlushDone();
+  }
+}
+
+void VideoDecoderProxy::OnResetComplete() {
+  DCHECK(RenderThreadImpl::current());
+  DCHECK(host_);
+
+  while (!pending_frames_.empty()) {
+    scoped_ptr<PendingFrame> frame(pending_frames_.front());
+    host_->NotifyEndOfBitstreamBuffer(frame->decode_id);

[Ami GONE FROM CHROMIUM, 2014/06/05 00:06:24]

Not sure this is necessary, FWIW.

[bbudge, 2014/06/06 02:03:44]

It makes it a little simpler in the host, since I don't need special code to
return all shm buffers to the available list.

+    pending_frames_.pop();
+  }
+
+  state_ = DECODING;
+  host_->NotifyResetDone();
+}
+
+void VideoDecoderProxy::DismissTexture(uint32_t texture_id) {
+  DCHECK(host_);
+  textures_to_dismiss_.erase(texture_id);
+  DCHECK(texture_id_map_.find(texture_id) != texture_id_map_.end());
+  DeleteTexture(texture_id_map_[texture_id]);
+  texture_id_map_.erase(texture_id);
+  host_->DismissPictureBuffer(texture_id);
+}
+
+void VideoDecoderProxy::DeleteTexture(uint32_t texture_id) {
+  gpu::gles2::GLES2Interface* gles2 = context_provider_->ContextGL();
+  gles2->DeleteTextures(1, &texture_id);
+}
+
+void VideoDecoderProxy::FlushCommandBuffer() {
+  DCHECK(RenderThreadImpl::current());
+  context_provider_->ContextGL()->Flush();
+}
+
+}  // namespace content