Break tight coupling of VideoCaptureDeviceClient to renderer_host

content/browser/renderer_host/media/video_capture_buffer_pool.cc

 // Copyright (c) 2013 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_buffer_pool.h"
 
 #include <memory>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "build/build_config.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "ui/gfx/buffer_format_util.h"
 
 namespace content {
 
-const int VideoCaptureBufferPool::kInvalidId = -1;
-
 // Tracker specifics for SharedMemory.
 class VideoCaptureBufferPool::SharedMemTracker final : public Tracker {
  public:
   SharedMemTracker() : Tracker() {}
 
   bool Init(const gfx::Size& dimensions,
             media::VideoPixelFormat format,
             media::VideoPixelStorage storage_type,
             base::Lock* lock) override {
     DVLOG(2) << "allocating ShMem of " << dimensions.ToString();
@@ skipping 347 matching lines @@
       it->second->storage_type() == storage) {
     it->second->set_held_by_producer(true);
     const int resurrected_buffer_id = last_relinquished_buffer_id_;
     last_relinquished_buffer_id_ = kInvalidId;
     return resurrected_buffer_id;
   }
 
   return kInvalidId;
 }
 
-double VideoCaptureBufferPool::GetBufferPoolUtilization() const {
+double VideoCaptureBufferPool::GetBufferPoolUtilization() {
   base::AutoLock lock(lock_);
   int num_buffers_held = 0;
   for (const auto& entry : trackers_) {
     Tracker* const tracker = entry.second;
     if (tracker->held_by_producer() || tracker->consumer_hold_count() > 0)
       ++num_buffers_held;
   }
   return static_cast<double>(num_buffers_held) / count_;
 }
 
@@ skipping 75 matching lines @@
   return buffer_id;
 }
 
 VideoCaptureBufferPool::Tracker* VideoCaptureBufferPool::GetTracker(
     int buffer_id) {
   TrackerMap::const_iterator it = trackers_.find(buffer_id);
   return (it == trackers_.end()) ? NULL : it->second;
 }
 
 }  // namespace content