Add Resource Handler for creating Streams to forward to extensions

content/browser/streams/stream.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/streams/stream.h"
 
 #include "base/bind.h"
 #include "base/message_loop_proxy.h"
 #include "content/browser/streams/stream_read_observer.h"
 #include "content/browser/streams/stream_registry.h"
@@ skipping 87 matching lines @@
   bytes_read_ += to_read;
   if (bytes_read_ >= data_length_)
     data_ = NULL;
 
   *bytes_read = to_read;
   return STREAM_HAS_DATA;
 }
 
 void Stream::OnSpaceAvailable() {
   can_add_data_ = true;
-  write_observer_->OnSpaceAvailable(this);
+  if (write_observer_)
+    write_observer_->OnSpaceAvailable(this);
 }
 
 void Stream::OnDataAvailable() {
   if (read_observer_)
     read_observer_->OnDataAvailable(this);
 }
 
 }  // namespace content