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

media/gpu/fake_jpeg_decode_accelerator.h

+// Copyright 2017 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.
+
+#ifndef MEDIA_GPU_FAKE_JPEG_DECODE_ACCELERATOR_H_
+#define MEDIA_GPU_FAKE_JPEG_DECODE_ACCELERATOR_H_
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "media/base/bitstream_buffer.h"
+#include "media/gpu/media_gpu_export.h"
+#include "media/video/jpeg_decode_accelerator.h"
+
+namespace media {
+
+// Uses software-based decoding. The purpose of this class is to enable testing
+// of communication to the JpegDecodeAccelerator without requiring an actual
+// hardware decoder.
+class MEDIA_GPU_EXPORT FakeJpegDecodeAccelerator
+    : public JpegDecodeAccelerator {
+ public:
+  FakeJpegDecodeAccelerator(
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+  ~FakeJpegDecodeAccelerator() override;
+
+  // JpegDecodeAccelerator implementation.
+  bool Initialize(JpegDecodeAccelerator::Client* client) override;
+  void Decode(const BitstreamBuffer& bitstream_buffer,
+              const scoped_refptr<VideoFrame>& video_frame) override;
+  bool IsSupported() override;
+
+ private:
+  void NotifyErrorFromIoThread(int32_t bitstream_buffer_id, Error error);
+  void OnNotifyErrorOnClientThread(int32_t bitstream_buffer_id, Error error);
+  void OnDecodeDoneOnClientThread(int32_t input_buffer_id);
+
+  const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

[mcasas, 2017/03/07 19:39:38]

nit: Forward declare SingleThreadTaskRunner

[chfremer, 2017/03/07 22:30:38]

Done.

+  const scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+  Client* client_ = nullptr;
+
+  base::WeakPtrFactory<FakeJpegDecodeAccelerator> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeJpegDecodeAccelerator);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_GPU_FAKE_JPEG_DECODE_ACCELERATOR_H_