Bring back the URLLoader from the old Mandoline network service.

content/network/net_adapters.cc

Index: content/network/net_adapters.cc
diff --git a/content/network/net_adapters.cc b/content/network/net_adapters.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1481b53b13af11f6514bf9e9d12aa2a42dd93626
--- /dev/null
+++ b/content/network/net_adapters.cc
@@ -0,0 +1,54 @@
+// 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/net_adapters.h"
+
+#include "net/base/net_errors.h"
+
+namespace content {
+
+namespace {
+const uint32_t kMaxBufSize = 64 * 1024;
+}
+
+NetToMojoPendingBuffer::NetToMojoPendingBuffer(
+    mojo::ScopedDataPipeProducerHandle handle,
+    void* buffer)
+    : handle_(std::move(handle)), buffer_(buffer) {}
+
+NetToMojoPendingBuffer::~NetToMojoPendingBuffer() {
+  if (handle_.is_valid())
+    EndWriteDataRaw(handle_.get(), 0);
+}
+
+MojoResult NetToMojoPendingBuffer::BeginWrite(
+    mojo::ScopedDataPipeProducerHandle* handle,
+    scoped_refptr<NetToMojoPendingBuffer>* pending,
+    uint32_t* num_bytes) {
+  void* buf;
+  *num_bytes = 0;
+  MojoResult result = BeginWriteDataRaw(handle->get(), &buf, num_bytes,
+                                        MOJO_WRITE_DATA_FLAG_NONE);
+  if (result == MOJO_RESULT_OK) {
+    if (*num_bytes > kMaxBufSize)
+      *num_bytes = kMaxBufSize;
+    *pending = new NetToMojoPendingBuffer(std::move(*handle), buf);
+  }
+  return result;
+}
+
+mojo::ScopedDataPipeProducerHandle NetToMojoPendingBuffer::Complete(
+    uint32_t num_bytes) {
+  EndWriteDataRaw(handle_.get(), num_bytes);
+  buffer_ = NULL;
+  return std::move(handle_);
+}
+
+NetToMojoIOBuffer::NetToMojoIOBuffer(NetToMojoPendingBuffer* pending_buffer)
+    : net::WrappedIOBuffer(pending_buffer->buffer()),
+      pending_buffer_(pending_buffer) {}
+
+NetToMojoIOBuffer::~NetToMojoIOBuffer() {}
+
+}  // namespace content