[Mojo Video Capture] Move SharedMem Tracker/BufferHandle/Factory from content to media

content/browser/renderer_host/media/shared_memory_buffer_tracker.cc

-// Copyright 2016 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/shared_memory_buffer_tracker.h"
-
-#include "base/memory/ptr_util.h"
-#include "content/browser/renderer_host/media/shared_memory_buffer_handle.h"
-#include "mojo/public/cpp/system/platform_handle.h"
-
-namespace content {
-
-SharedMemoryBufferTracker::SharedMemoryBufferTracker()
-    : VideoCaptureBufferTracker() {}
-
-bool SharedMemoryBufferTracker::Init(const gfx::Size& dimensions,
-                                     media::VideoPixelFormat format,
-                                     media::VideoPixelStorage storage_type,
-                                     base::Lock* lock) {
-  DVLOG(2) << __func__ << "allocating ShMem of " << dimensions.ToString();
-  set_dimensions(dimensions);
-  // |dimensions| can be 0x0 for trackers that do not require memory backing.
-  set_max_pixel_count(dimensions.GetArea());
-  set_pixel_format(format);
-  set_storage_type(storage_type);
-  mapped_size_ =
-      media::VideoCaptureFormat(dimensions, 0.0f, format, storage_type)
-          .ImageAllocationSize();
-  if (!mapped_size_)
-    return true;
-  return shared_memory_.CreateAndMapAnonymous(mapped_size_);
-}
-
-std::unique_ptr<media::VideoCaptureBufferHandle>
-SharedMemoryBufferTracker::GetBufferHandle() {
-  return base::MakeUnique<SharedMemoryBufferHandle>(this);
-}
-
-mojo::ScopedSharedBufferHandle
-SharedMemoryBufferTracker::GetHandleForTransit() {
-  return mojo::WrapSharedMemoryHandle(
-      base::SharedMemory::DuplicateHandle(shared_memory_.handle()),
-      mapped_size_, false /* read_only */);
-}
-
-}  // namespace content