Revert of content/common: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

content/common/gpu/media/v4l2_video_decode_accelerator.cc

 // 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.
 
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
+#include "base/message_loop/message_loop_proxy.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "content/common/gpu/media/v4l2_video_decode_accelerator.h"
 #include "media/base/media_switches.h"
 #include "media/filters/h264_parser.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gl/scoped_binders.h"
 
 #define NOTIFY_ERROR(x)                        \
   do {                                         \
@@ skipping 29 matching lines @@
 // TODO(posciak): remove once we update linux-headers.
 #ifndef V4L2_EVENT_RESOLUTION_CHANGE
 #define V4L2_EVENT_RESOLUTION_CHANGE 5
 #endif
 
 }  // anonymous namespace
 
 struct V4L2VideoDecodeAccelerator::BitstreamBufferRef {
   BitstreamBufferRef(
       base::WeakPtr<Client>& client,
-      scoped_refptr<base::SingleThreadTaskRunner>& client_task_runner,
+      scoped_refptr<base::MessageLoopProxy>& client_message_loop_proxy,
       base::SharedMemory* shm,
       size_t size,
       int32 input_id);
   ~BitstreamBufferRef();
   const base::WeakPtr<Client> client;
-  const scoped_refptr<base::SingleThreadTaskRunner> client_task_runner;
+  const scoped_refptr<base::MessageLoopProxy> client_message_loop_proxy;
   const scoped_ptr<base::SharedMemory> shm;
   const size_t size;
   size_t bytes_used;
   const int32 input_id;
 };
 
 struct V4L2VideoDecodeAccelerator::EGLSyncKHRRef {
   EGLSyncKHRRef(EGLDisplay egl_display, EGLSyncKHR egl_sync);
   ~EGLSyncKHRRef();
   EGLDisplay const egl_display;
   EGLSyncKHR egl_sync;
 };
 
 struct V4L2VideoDecodeAccelerator::PictureRecord {
   PictureRecord(bool cleared, const media::Picture& picture);
   ~PictureRecord();
   bool cleared;  // Whether the texture is cleared and safe to render from.
   media::Picture picture;  // The decoded picture.
 };
 
 V4L2VideoDecodeAccelerator::BitstreamBufferRef::BitstreamBufferRef(
     base::WeakPtr<Client>& client,
-    scoped_refptr<base::SingleThreadTaskRunner>& client_task_runner,
-    base::SharedMemory* shm,
-    size_t size,
-    int32 input_id)
+    scoped_refptr<base::MessageLoopProxy>& client_message_loop_proxy,
+    base::SharedMemory* shm, size_t size, int32 input_id)
     : client(client),
-      client_task_runner(client_task_runner),
+      client_message_loop_proxy(client_message_loop_proxy),
       shm(shm),
       size(size),
       bytes_used(0),
       input_id(input_id) {
 }
 
 V4L2VideoDecodeAccelerator::BitstreamBufferRef::~BitstreamBufferRef() {
   if (input_id >= 0) {
-    client_task_runner->PostTask(
-        FROM_HERE,
-        base::Bind(&Client::NotifyEndOfBitstreamBuffer, client, input_id));
+    client_message_loop_proxy->PostTask(FROM_HERE, base::Bind(
+        &Client::NotifyEndOfBitstreamBuffer, client, input_id));
   }
 }
 
 V4L2VideoDecodeAccelerator::EGLSyncKHRRef::EGLSyncKHRRef(
     EGLDisplay egl_display, EGLSyncKHR egl_sync)
     : egl_display(egl_display),
       egl_sync(egl_sync) {
 }
 
 V4L2VideoDecodeAccelerator::EGLSyncKHRRef::~EGLSyncKHRRef() {
@@ skipping 32 matching lines @@
     : cleared(cleared), picture(picture) {}
 
 V4L2VideoDecodeAccelerator::PictureRecord::~PictureRecord() {}
 
 V4L2VideoDecodeAccelerator::V4L2VideoDecodeAccelerator(
     EGLDisplay egl_display,
     EGLContext egl_context,
     const base::WeakPtr<Client>& io_client,
     const base::Callback<bool(void)>& make_context_current,
     const scoped_refptr<V4L2Device>& device,
-    const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
-    : child_task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      io_task_runner_(io_task_runner),
+    const scoped_refptr<base::MessageLoopProxy>& io_message_loop_proxy)
+    : child_message_loop_proxy_(base::MessageLoopProxy::current()),
+      io_message_loop_proxy_(io_message_loop_proxy),
       io_client_(io_client),
       decoder_thread_("V4L2DecoderThread"),
       decoder_state_(kUninitialized),
       device_(device),
       decoder_delay_bitstream_buffer_id_(-1),
       decoder_current_input_buffer_(-1),
       decoder_decode_buffer_tasks_scheduled_(0),
       decoder_frames_at_client_(0),
       decoder_flushing_(false),
       resolution_change_pending_(false),
@@ skipping 26 matching lines @@
 
   // These maps have members that should be manually destroyed, e.g. file
   // descriptors, mmap() segments, etc.
   DCHECK(input_buffer_map_.empty());
   DCHECK(output_buffer_map_.empty());
 }
 
 bool V4L2VideoDecodeAccelerator::Initialize(media::VideoCodecProfile profile,
                                             Client* client) {
   DVLOG(3) << "Initialize()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   DCHECK_EQ(decoder_state_, kUninitialized);
 
   client_ptr_factory_.reset(new base::WeakPtrFactory<Client>(client));
   client_ = client_ptr_factory_->GetWeakPtr();
 
   switch (profile) {
     case media::H264PROFILE_BASELINE:
       DVLOG(2) << "Initialize(): profile H264PROFILE_BASELINE";
       break;
     case media::H264PROFILE_MAIN:
@@ skipping 77 matching lines @@
           base::IgnoreResult(&V4L2VideoDecodeAccelerator::StartDevicePoll),
           base::Unretained(this)));
 
   return true;
 }
 
 void V4L2VideoDecodeAccelerator::Decode(
     const media::BitstreamBuffer& bitstream_buffer) {
   DVLOG(1) << "Decode(): input_id=" << bitstream_buffer.id()
            << ", size=" << bitstream_buffer.size();
-  DCHECK(io_task_runner_->BelongsToCurrentThread());
+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
 
   // DecodeTask() will take care of running a DecodeBufferTask().
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::DecodeTask, base::Unretained(this),
       bitstream_buffer));
 }
 
 void V4L2VideoDecodeAccelerator::AssignPictureBuffers(
     const std::vector<media::PictureBuffer>& buffers) {
   DVLOG(3) << "AssignPictureBuffers(): buffer_count=" << buffers.size();
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
 
   if (buffers.size() != output_buffer_map_.size()) {
     LOG(ERROR) << "AssignPictureBuffers(): Failed to provide requested picture"
                   " buffers. (Got " << buffers.size()
                << ", requested " << output_buffer_map_.size() << ")";
     NOTIFY_ERROR(INVALID_ARGUMENT);
     return;
   }
 
   if (!make_context_current_.Run()) {
@@ skipping 40 matching lines @@
     DVLOG(3) << "AssignPictureBuffers(): buffer[" << i
              << "]: picture_id=" << output_record.picture_id;
   }
 
   pictures_assigned_.Signal();
 }
 
 void V4L2VideoDecodeAccelerator::ReusePictureBuffer(int32 picture_buffer_id) {
   DVLOG(3) << "ReusePictureBuffer(): picture_buffer_id=" << picture_buffer_id;
   // Must be run on child thread, as we'll insert a sync in the EGL context.
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
 
   if (!make_context_current_.Run()) {
     LOG(ERROR) << "ReusePictureBuffer(): could not make context current";
     NOTIFY_ERROR(PLATFORM_FAILURE);
     return;
   }
 
   EGLSyncKHR egl_sync = EGL_NO_SYNC_KHR;
 // TODO(posciak): crbug.com/450898.
 #if defined(ARCH_CPU_ARMEL)
   egl_sync = eglCreateSyncKHR(egl_display_, EGL_SYNC_FENCE_KHR, NULL);
   if (egl_sync == EGL_NO_SYNC_KHR) {
     LOG(ERROR) << "ReusePictureBuffer(): eglCreateSyncKHR() failed";
     NOTIFY_ERROR(PLATFORM_FAILURE);
     return;
   }
 #endif
 
   scoped_ptr<EGLSyncKHRRef> egl_sync_ref(new EGLSyncKHRRef(
       egl_display_, egl_sync));
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::ReusePictureBufferTask,
       base::Unretained(this), picture_buffer_id, base::Passed(&egl_sync_ref)));
 }
 
 void V4L2VideoDecodeAccelerator::Flush() {
   DVLOG(3) << "Flush()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::FlushTask, base::Unretained(this)));
 }
 
 void V4L2VideoDecodeAccelerator::Reset() {
   DVLOG(3) << "Reset()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::ResetTask, base::Unretained(this)));
 }
 
 void V4L2VideoDecodeAccelerator::Destroy() {
   DVLOG(3) << "Destroy()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
 
   // We're destroying; cancel all callbacks.
   client_ptr_factory_.reset();
   weak_this_factory_.InvalidateWeakPtrs();
 
   // If the decoder thread is running, destroy using posted task.
   if (decoder_thread_.IsRunning()) {
     decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
         &V4L2VideoDecodeAccelerator::DestroyTask, base::Unretained(this)));
     pictures_assigned_.Signal();
@@ skipping 24 matching lines @@
 
 void V4L2VideoDecodeAccelerator::DecodeTask(
     const media::BitstreamBuffer& bitstream_buffer) {
   DVLOG(3) << "DecodeTask(): input_id=" << bitstream_buffer.id();
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_NE(decoder_state_, kUninitialized);
   TRACE_EVENT1("Video Decoder", "V4L2VDA::DecodeTask", "input_id",
                bitstream_buffer.id());
 
   scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
-      io_client_, io_task_runner_,
+      io_client_, io_message_loop_proxy_,
       new base::SharedMemory(bitstream_buffer.handle(), true),
       bitstream_buffer.size(), bitstream_buffer.id()));
   if (!bitstream_record->shm->Map(bitstream_buffer.size())) {
     LOG(ERROR) << "Decode(): could not map bitstream_buffer";
     NOTIFY_ERROR(UNREADABLE_INPUT);
     return;
   }
   DVLOG(3) << "DecodeTask(): mapped at=" << bitstream_record->shm->memory();
 
   if (decoder_state_ == kResetting || decoder_flushing_) {
@@ skipping 756 matching lines @@
 
 void V4L2VideoDecodeAccelerator::FlushTask() {
   DVLOG(3) << "FlushTask()";
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   TRACE_EVENT0("Video Decoder", "V4L2VDA::FlushTask");
 
   // Flush outstanding buffers.
   if (decoder_state_ == kInitialized || decoder_state_ == kAfterReset) {
     // There's nothing in the pipe, so return done immediately.
     DVLOG(3) << "FlushTask(): returning flush";
-    child_task_runner_->PostTask(FROM_HERE,
-                                 base::Bind(&Client::NotifyFlushDone, client_));
+    child_message_loop_proxy_->PostTask(
+        FROM_HERE, base::Bind(&Client::NotifyFlushDone, client_));
     return;
   } else if (decoder_state_ == kError) {
     DVLOG(2) << "FlushTask(): early out: kError state";
     return;
   }
 
   // We don't support stacked flushing.
   DCHECK(!decoder_flushing_);
 
   // Queue up an empty buffer -- this triggers the flush.
   decoder_input_queue_.push(
       linked_ptr<BitstreamBufferRef>(new BitstreamBufferRef(
-          io_client_, io_task_runner_, NULL, 0, kFlushBufferId)));
+          io_client_, io_message_loop_proxy_, NULL, 0, kFlushBufferId)));
   decoder_flushing_ = true;
   SendPictureReady();  // Send all pending PictureReady.
 
   ScheduleDecodeBufferTaskIfNeeded();
 }
 
 void V4L2VideoDecodeAccelerator::NotifyFlushDoneIfNeeded() {
   if (!decoder_flushing_)
     return;
 
@@ skipping 23 matching lines @@
   // when doing MSE. This should be harmless otherwise.
   if (!StopDevicePoll(false))
     return;
 
   if (!StartDevicePoll())
     return;
 
   decoder_delay_bitstream_buffer_id_ = -1;
   decoder_flushing_ = false;
   DVLOG(3) << "NotifyFlushDoneIfNeeded(): returning flush";
-  child_task_runner_->PostTask(FROM_HERE,
-                               base::Bind(&Client::NotifyFlushDone, client_));
+  child_message_loop_proxy_->PostTask(
+      FROM_HERE, base::Bind(&Client::NotifyFlushDone, client_));
 
   // While we were flushing, we early-outed DecodeBufferTask()s.
   ScheduleDecodeBufferTaskIfNeeded();
 }
 
 void V4L2VideoDecodeAccelerator::ResetTask() {
   DVLOG(3) << "ResetTask()";
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   TRACE_EVENT0("Video Decoder", "V4L2VDA::ResetTask");
 
@@ skipping 65 matching lines @@
   if (output_buffer_map_.empty()) {
     // We must have gotten Reset() before we had a chance to request buffers
     // from the client.
     decoder_state_ = kInitialized;
   } else {
     decoder_state_ = kAfterReset;
   }
 
   decoder_partial_frame_pending_ = false;
   decoder_delay_bitstream_buffer_id_ = -1;
-  child_task_runner_->PostTask(FROM_HERE,
-                               base::Bind(&Client::NotifyResetDone, client_));
+  child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &Client::NotifyResetDone, client_));
 
   // While we were resetting, we early-outed DecodeBufferTask()s.
   ScheduleDecodeBufferTaskIfNeeded();
 }
 
 void V4L2VideoDecodeAccelerator::DestroyTask() {
   DVLOG(3) << "DestroyTask()";
   TRACE_EVENT0("Video Decoder", "V4L2VDA::DestroyTask");
 
   // DestroyTask() should run regardless of decoder_state_.
@@ skipping 114 matching lines @@
   // Keep input queue.
   if (!StopDevicePoll(true))
     return;
 
   decoder_state_ = kChangingResolution;
   DCHECK(resolution_change_pending_);
   resolution_change_pending_ = false;
 
   // Post a task to clean up buffers on child thread. This will also ensure
   // that we won't accept ReusePictureBuffer() anymore after that.
-  child_task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&V4L2VideoDecodeAccelerator::ResolutionChangeDestroyBuffers,
-                 weak_this_));
+  child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &V4L2VideoDecodeAccelerator::ResolutionChangeDestroyBuffers,
+      weak_this_));
 }
 
 void V4L2VideoDecodeAccelerator::FinishResolutionChange() {
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   DCHECK_EQ(decoder_state_, kChangingResolution);
   DVLOG(3) << "FinishResolutionChange()";
 
   if (decoder_state_ == kError) {
     DVLOG(2) << "FinishResolutionChange(): early out: kError state";
     return;
@@ skipping 45 matching lines @@
   // All processing should happen on ServiceDeviceTask(), since we shouldn't
   // touch decoder state from this thread.
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::ServiceDeviceTask,
       base::Unretained(this), event_pending));
 }
 
 void V4L2VideoDecodeAccelerator::NotifyError(Error error) {
   DVLOG(2) << "NotifyError()";
 
-  if (!child_task_runner_->BelongsToCurrentThread()) {
-    child_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&V4L2VideoDecodeAccelerator::NotifyError,
-                              weak_this_, error));
+  if (!child_message_loop_proxy_->BelongsToCurrentThread()) {
+    child_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+        &V4L2VideoDecodeAccelerator::NotifyError, weak_this_, error));
     return;
   }
 
   if (client_) {
     client_->NotifyError(error);
     client_ptr_factory_.reset();
   }
 }
 
 void V4L2VideoDecodeAccelerator::SetErrorState(Error error) {
@@ skipping 226 matching lines @@
   reqbufs.count  = output_dpb_size_ + kDpbOutputBufferExtraCount;
   reqbufs.type   = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
   reqbufs.memory = V4L2_MEMORY_MMAP;
   IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_REQBUFS, &reqbufs);
 
   output_buffer_map_.resize(reqbufs.count);
 
   DVLOG(3) << "CreateOutputBuffers(): ProvidePictureBuffers(): "
            << "buffer_count=" << output_buffer_map_.size()
            << ", coded_size=" << coded_size_.ToString();
-  child_task_runner_->PostTask(
-      FROM_HERE, base::Bind(&Client::ProvidePictureBuffers, client_,
-                            output_buffer_map_.size(), coded_size_,
-                            device_->GetTextureTarget()));
+  child_message_loop_proxy_->PostTask(FROM_HERE,
+                                      base::Bind(&Client::ProvidePictureBuffers,
+                                                 client_,
+                                                 output_buffer_map_.size(),
+                                                 coded_size_,
+                                                 device_->GetTextureTarget()));
 
   // Wait for the client to call AssignPictureBuffers() on the Child thread.
   // We do this, because if we continue decoding without finishing buffer
   // allocation, we may end up Resetting before AssignPictureBuffers arrives,
   // resulting in unnecessary complications and subtle bugs.
   // For example, if the client calls Decode(Input1), Reset(), Decode(Input2)
   // in a sequence, and Decode(Input1) results in us getting here and exiting
   // without waiting, we might end up running Reset{,Done}Task() before
   // AssignPictureBuffers is scheduled, thus cleaning up and pushing buffers
   // to the free_output_buffers_ map twice. If we somehow marked buffers as
   // not ready, we'd need special handling for restarting the second Decode
   // task and delaying it anyway.
   // Waiting here is not very costly and makes reasoning about different
   // situations much simpler.
   pictures_assigned_.Wait();
 
   Enqueue();
   return true;
 }
 
 void V4L2VideoDecodeAccelerator::DestroyInputBuffers() {
   DVLOG(3) << "DestroyInputBuffers()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   DCHECK(!input_streamon_);
 
   for (size_t i = 0; i < input_buffer_map_.size(); ++i) {
     if (input_buffer_map_[i].address != NULL) {
       device_->Munmap(input_buffer_map_[i].address,
                       input_buffer_map_[i].length);
     }
   }
 
   struct v4l2_requestbuffers reqbufs;
   memset(&reqbufs, 0, sizeof(reqbufs));
   reqbufs.count = 0;
   reqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
   reqbufs.memory = V4L2_MEMORY_MMAP;
   IOCTL_OR_LOG_ERROR(VIDIOC_REQBUFS, &reqbufs);
 
   input_buffer_map_.clear();
   free_input_buffers_.clear();
 }
 
 bool V4L2VideoDecodeAccelerator::DestroyOutputBuffers() {
   DVLOG(3) << "DestroyOutputBuffers()";
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   DCHECK(!output_streamon_);
   bool success = true;
 
   for (size_t i = 0; i < output_buffer_map_.size(); ++i) {
     OutputRecord& output_record = output_buffer_map_[i];
 
     if (output_record.egl_image != EGL_NO_IMAGE_KHR) {
       if (device_->DestroyEGLImage(egl_display_, output_record.egl_image) !=
           EGL_TRUE) {
         DVLOG(1) << __func__ << " DestroyEGLImage failed.";
         success = false;
       }
     }
 
     if (output_record.egl_sync != EGL_NO_SYNC_KHR) {
       if (eglDestroySyncKHR(egl_display_, output_record.egl_sync) != EGL_TRUE) {
         DVLOG(1) << __func__ << " eglDestroySyncKHR failed.";
         success = false;
       }
     }
 
     DVLOG(1) << "DestroyOutputBuffers(): dismissing PictureBuffer id="
              << output_record.picture_id;
-    child_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&Client::DismissPictureBuffer, client_,
-                              output_record.picture_id));
+    child_message_loop_proxy_->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &Client::DismissPictureBuffer, client_, output_record.picture_id));
   }
 
   struct v4l2_requestbuffers reqbufs;
   memset(&reqbufs, 0, sizeof(reqbufs));
   reqbufs.count = 0;
   reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
   reqbufs.memory = V4L2_MEMORY_MMAP;
   if (device_->Ioctl(VIDIOC_REQBUFS, &reqbufs) != 0) {
     PLOG(ERROR) << "DestroyOutputBuffers() ioctl() failed: VIDIOC_REQBUFS";
     success = false;
   }
 
   output_buffer_map_.clear();
   while (!free_output_buffers_.empty())
     free_output_buffers_.pop();
 
   return success;
 }
 
 void V4L2VideoDecodeAccelerator::ResolutionChangeDestroyBuffers() {
-  DCHECK(child_task_runner_->BelongsToCurrentThread());
+  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   DVLOG(3) << "ResolutionChangeDestroyBuffers()";
 
   if (!DestroyOutputBuffers()) {
     LOG(ERROR) << __func__ << " Failed destroying output buffers.";
     NOTIFY_ERROR(PLATFORM_FAILURE);
     return;
   }
 
   // Finish resolution change on decoder thread.
   decoder_thread_.message_loop()->PostTask(FROM_HERE, base::Bind(
       &V4L2VideoDecodeAccelerator::FinishResolutionChange,
       base::Unretained(this)));
 }
 
 void V4L2VideoDecodeAccelerator::SendPictureReady() {
   DVLOG(3) << "SendPictureReady()";
   DCHECK_EQ(decoder_thread_.message_loop(), base::MessageLoop::current());
   bool resetting_or_flushing =
       (decoder_state_ == kResetting || decoder_flushing_);
   while (pending_picture_ready_.size() > 0) {
     bool cleared = pending_picture_ready_.front().cleared;
     const media::Picture& picture = pending_picture_ready_.front().picture;
     if (cleared && picture_clearing_count_ == 0) {
       // This picture is cleared. Post it to IO thread to reduce latency. This
       // should be the case after all pictures are cleared at the beginning.
-      io_task_runner_->PostTask(
+      io_message_loop_proxy_->PostTask(
           FROM_HERE, base::Bind(&Client::PictureReady, io_client_, picture));
       pending_picture_ready_.pop();
     } else if (!cleared || resetting_or_flushing) {
       DVLOG(3) << "SendPictureReady()"
                << ". cleared=" << pending_picture_ready_.front().cleared
                << ", decoder_state_=" << decoder_state_
                << ", decoder_flushing_=" << decoder_flushing_
                << ", picture_clearing_count_=" << picture_clearing_count_;
       // If the picture is not cleared, post it to the child thread because it
       // has to be cleared in the child thread. A picture only needs to be
       // cleared once. If the decoder is resetting or flushing, send all
       // pictures to ensure PictureReady arrive before reset or flush done.
-      child_task_runner_->PostTaskAndReply(
-          FROM_HERE, base::Bind(&Client::PictureReady, client_, picture),
+      child_message_loop_proxy_->PostTaskAndReply(
+          FROM_HERE,
+          base::Bind(&Client::PictureReady, client_, picture),
           // Unretained is safe. If Client::PictureReady gets to run, |this| is
           // alive. Destroy() will wait the decode thread to finish.
           base::Bind(&V4L2VideoDecodeAccelerator::PictureCleared,
                      base::Unretained(this)));
       picture_clearing_count_++;
       pending_picture_ready_.pop();
     } else {
       // This picture is cleared. But some pictures are about to be cleared on
       // the child thread. To preserve the order, do not send this until those
       // pictures are cleared.
@@ skipping 32 matching lines @@
   gfx::Size new_coded_size(base::checked_cast<int>(format.fmt.pix_mp.width),
                            base::checked_cast<int>(format.fmt.pix_mp.height));
   if (coded_size_ != new_coded_size) {
     DVLOG(3) << "IsResolutionChangeNecessary(): Resolution change detected";
     return true;
   }
   return false;
 }
 
 }  // namespace content