Avoid issuing a Read() after draining a request.

content/browser/loader/buffered_resource_handler.cc

 // Copyright (c) 2012 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/loader/buffered_resource_handler.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 441 matching lines @@
       request()->url(), GURL(), response_->head.mime_type, allow_wildcard,
       stale, &plugin, NULL);
 #else
   if (stale)
     *stale = false;
   return false;
 #endif
 }
 
 bool BufferedResourceHandler::CopyReadBufferToNextHandler(int request_id) {
-  if (!bytes_read_)
+  if (!read_buffer_.get())
     return true;
 
   scoped_refptr<net::IOBuffer> buf;
   int buf_len = 0;
   if (!next_handler_->OnWillRead(request_id, &buf, &buf_len, bytes_read_))
     return false;
 
   CHECK((buf_len >= bytes_read_) && (bytes_read_ >= 0));
   memcpy(buf->data(), read_buffer_->data(), bytes_read_);
   return true;
 }
 
 void BufferedResourceHandler::OnPluginsLoaded(
     const std::vector<WebPluginInfo>& plugins) {
   request()->LogUnblocked();
   bool defer = false;
   if (!ProcessResponse(&defer)) {
     controller()->Cancel();
   } else if (!defer) {
     controller()->Resume();
   }
 }
 
 }  // namespace content