Add CHECKs to help debug crashes exposed by adding a member to IPC::Message::Header.

content/child/resource_dispatcher.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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "content/child/resource_dispatcher.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ skipping 203 matching lines @@
                                         int data_offset,
                                         int data_length,
                                         int encoded_data_length) {
   TRACE_EVENT0("loader", "ResourceDispatcher::OnReceivedData");
   DCHECK_GT(data_length, 0);
   PendingRequestInfo* request_info = GetPendingRequestInfo(request_id);
   bool send_ack = true;
   if (request_info && data_length > 0) {
     CHECK(base::SharedMemory::IsHandleValid(request_info->buffer->handle()));
     CHECK_GE(request_info->buffer_size, data_offset + data_length);
+    // TODO(erikchen): Temporary debugging for http://crbug.com/527588.
+    CHECK_LE(data_offset, 512 * 1024);
 
     // Ensure that the SHM buffer remains valid for the duration of this scope.
     // It is possible for Cancel() to be called before we exit this scope.
     // SharedMemoryReceivedDataFactory stores the SHM buffer inside it.
     scoped_refptr<SharedMemoryReceivedDataFactory> factory(
         request_info->received_data_factory);
 
     base::TimeTicks time_start = base::TimeTicks::Now();
 
     const char* data_start = static_cast<char*>(request_info->buffer->memory());
@@ skipping 554 matching lines @@
       extra_data->transferred_request_request_id();
   request->service_worker_provider_id =
       extra_data->service_worker_provider_id();
   request->request_body = request_body;
   if (frame_origin)
     *frame_origin = extra_data->frame_origin();
   return request.Pass();
 }
 
 }  // namespace content