[Mojo Video Capture] Add test coverage for accelerated jpeg decoding

content/browser/renderer_host/media/video_capture_gpu_jpeg_decoder.cc

 // Copyright 2015 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 "content/browser/renderer_host/media/video_capture_gpu_jpeg_decoder.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
+#include "media/base/media_switches.h"
 #include "media/base/video_frame.h"
 #include "media/gpu/ipc/client/gpu_jpeg_decode_accelerator_host.h"
 #include "mojo/public/cpp/system/platform_handle.h"
 
 namespace content {
 
 VideoCaptureGpuJpegDecoder::VideoCaptureGpuJpegDecoder(
     const DecodeDoneCB& decode_done_cb)
     : decode_done_cb_(decode_done_cb),
       next_bitstream_buffer_id_(0),
       in_buffer_id_(media::JpegDecodeAccelerator::kInvalidBitstreamBufferId),
       decoder_status_(INIT_PENDING) {}
 
 VideoCaptureGpuJpegDecoder::~VideoCaptureGpuJpegDecoder() {
   DCHECK(CalledOnValidThread());
 
   // |decoder_| guarantees no more JpegDecodeAccelerator::Client callbacks
   // on IO thread after deletion.
   decoder_.reset();
 
   // |gpu_channel_host_| should outlive |decoder_|, so |gpu_channel_host_|
   // must be released after |decoder_| has been destroyed.
   gpu_channel_host_ = nullptr;
 }
 
 void VideoCaptureGpuJpegDecoder::Initialize() {
   DCHECK(CalledOnValidThread());
 
   base::AutoLock lock(lock_);
-  bool is_platform_supported = false;
+  bool is_platform_supported =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseFakeJpegDecodeAccelerator);
 #if defined(OS_CHROMEOS)
   // Non-ChromeOS platforms do not support HW JPEG decode now. Do not establish
   // gpu channel to avoid introducing overhead.
   is_platform_supported = true;
 #endif
 
   if (!is_platform_supported ||
       base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableAcceleratedMjpegDecode)) {
     decoder_status_ = FAILED;
@@ skipping 201 matching lines @@
   lock_.AssertAcquired();
   return !decode_done_closure_.is_null();
 }
 
 void VideoCaptureGpuJpegDecoder::RecordInitDecodeUMA_Locked() {
   UMA_HISTOGRAM_BOOLEAN("Media.VideoCaptureGpuJpegDecoder.InitDecodeSuccess",
                         decoder_status_ == INIT_PASSED);
 }
 
 }  // namespace content