media: Add UMA stats for bytes going in and out of multibuffer cache

media/blink/resource_multibuffer_data_provider.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 "media/blink/resource_multibuffer_data_provider.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 370 matching lines @@
   }
 }
 
 void ResourceMultiBufferDataProvider::DidReceiveData(const char* data,
                                                      int data_length) {
   DVLOG(1) << "didReceiveData: " << data_length << " bytes";
   DCHECK(!Available());
   DCHECK(active_loader_);
   DCHECK_GT(data_length, 0);
 
+  url_data_->AddBytesReadFromNetwork(data_length);
+
   if (bytes_to_discard_) {
     uint64_t tmp = std::min<uint64_t>(bytes_to_discard_, data_length);
     data_length -= tmp;
     data += tmp;
     bytes_to_discard_ -= tmp;
     if (data_length == 0)
       return;
   }
 
   // When we receive data, we allow more retries.
@@ skipping 176 matching lines @@
   }
   if (last_byte_position + 1 < byte_pos()) {
     return false;
   }
   bytes_to_discard_ = byte_pos() - first_byte_position;
 
   return true;
 }
 
 }  // namespace media