Reduce boilerplate when creating simple mojom::URLLoaders.

content/network/url_loader_impl.cc

 // Copyright 2017 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/network/url_loader_impl.h"
 
 #include "base/task_scheduler/post_task.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "content/common/url_loader_factory.mojom.h"
@@ skipping 250 matching lines @@
                                         std::move(downloaded_file_ptr));
 
   net::IOBufferWithSize* metadata = url_request->response_info().metadata.get();
   if (metadata) {
     const uint8_t* data = reinterpret_cast<const uint8_t*>(metadata->data());
 
     url_loader_client_->OnReceiveCachedMetadata(
         std::vector<uint8_t>(data, data + metadata->size()));
   }
 
-  MojoCreateDataPipeOptions options;
-  options.struct_size = sizeof(MojoCreateDataPipeOptions);
-  options.flags = MOJO_CREATE_DATA_PIPE_OPTIONS_FLAG_NONE;
-  options.element_num_bytes = 1;
-  options.capacity_num_bytes = kDefaultAllocationSize;
-  mojo::DataPipe data_pipe(options);
-
-  DCHECK(data_pipe.producer_handle.is_valid());
-  DCHECK(data_pipe.consumer_handle.is_valid());
+  mojo::DataPipe data_pipe(kDefaultAllocationSize);
 
   response_body_stream_ = std::move(data_pipe.producer_handle);
   response_body_consumer_handle_ = std::move(data_pipe.consumer_handle);
   peer_closed_handle_watcher_.Watch(
       response_body_stream_.get(), MOJO_HANDLE_SIGNAL_PEER_CLOSED,
       base::Bind(&URLLoaderImpl::OnResponseBodyStreamClosed,
                  base::Unretained(this)));
   peer_closed_handle_watcher_.ArmOrNotify();
 
   writable_handle_watcher_.Watch(
@@ skipping 113 matching lines @@
   ReadMore();
 }
 
 void URLLoaderImpl::DeleteIfNeeded() {
   bool has_data_pipe = pending_write_.get() || response_body_stream_.is_valid();
   if (!connected_ && !has_data_pipe)
     delete this;
 }
 
 }  // namespace content