[PPAPI][MediaStream] Support configure for video input.

ppapi/shared_impl/media_stream_buffer_manager.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 "ppapi/shared_impl/media_stream_buffer_manager.h"
 
 #include "base/logging.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/shared_impl/media_stream_buffer.h"
 
 namespace ppapi {
 
 MediaStreamBufferManager::Delegate::~Delegate() {}
 
 void MediaStreamBufferManager::Delegate::OnNewBufferEnqueued() {}
 
 MediaStreamBufferManager::MediaStreamBufferManager(Delegate* delegate)
     : delegate_(delegate), buffer_size_(0), number_of_buffers_(0) {
   DCHECK(delegate_);
 }
 
 MediaStreamBufferManager::~MediaStreamBufferManager() {}
 
 bool MediaStreamBufferManager::SetBuffers(int32_t number_of_buffers,
                                           int32_t buffer_size,
                                           scoped_ptr<base::SharedMemory> shm,
                                           bool enqueue_all_buffers) {
   DCHECK(shm);
-  DCHECK(!shm_);
   DCHECK_GT(number_of_buffers, 0);
   DCHECK_GT(buffer_size,
             static_cast<int32_t>(sizeof(MediaStreamBuffer::Header)));
   DCHECK_EQ(buffer_size & 0x3, 0);
 
   number_of_buffers_ = number_of_buffers;
   buffer_size_ = buffer_size;
 
-  int32_t size = number_of_buffers_ * buffer_size;
+  size_t size = number_of_buffers_ * buffer_size;
   shm_ = shm.Pass();
   if (!shm_->Map(size))
     return false;
 
+  buffer_queue_.clear();
+  buffers_.clear();
   uint8_t* p = reinterpret_cast<uint8_t*>(shm_->memory());
   for (int32_t i = 0; i < number_of_buffers; ++i) {
     if (enqueue_all_buffers)
       buffer_queue_.push_back(i);
     buffers_.push_back(reinterpret_cast<MediaStreamBuffer*>(p));
     p += buffer_size_;
   }
   return true;
 }
 
 int32_t MediaStreamBufferManager::DequeueBuffer() {
   if (buffer_queue_.empty())
     return PP_ERROR_FAILED;
   int32_t buffer = buffer_queue_.front();
   buffer_queue_.pop_front();
   return buffer;
 }
 
 void MediaStreamBufferManager::EnqueueBuffer(int32_t index) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, number_of_buffers_);
+  CHECK_GE(index, 0) << "Invalid buffer index";
+  CHECK_LT(index, number_of_buffers_) << "Invalid buffer index";
   buffer_queue_.push_back(index);
   delegate_->OnNewBufferEnqueued();
 }
 
-MediaStreamBuffer* MediaStreamBufferManager::GetBufferPointer(int32_t index) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, number_of_buffers_);
+MediaStreamBuffer* MediaStreamBufferManager::GetBufferPointer(
+    int32_t index) {
+  CHECK_GE(index, 0) << "Invalid buffer index";
+  CHECK_LT(index, number_of_buffers_) << "Invalid buffer index";
   return buffers_[index];
 }
 
 }  // namespace ppapi