Add new system url request context getter to the blimp engine.

blimp/engine/app/blimp_system_url_request_context_getter.cc

+// Copyright 2016 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 "blimp/engine/app/blimp_system_url_request_context_getter.h"
+
+#include <utility>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/single_thread_task_runner.h"
+#include "content/public/browser/browser_thread.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_builder.h"
+
+namespace blimp {
+namespace engine {
+
+BlimpSystemURLRequestContextGetter::BlimpSystemURLRequestContextGetter() {
+  // Must first be created on the UI thread.
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+}
+
+BlimpSystemURLRequestContextGetter::~BlimpSystemURLRequestContextGetter() {}
+
+net::URLRequestContext*
+BlimpSystemURLRequestContextGetter::GetURLRequestContext() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (!url_request_context_) {
+    // Use default values
+    net::URLRequestContextBuilder builder;
+    url_request_context_ = builder.Build();
+  }
+  return url_request_context_.get();
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+BlimpSystemURLRequestContextGetter::GetNetworkTaskRunner() const {
+  return content::BrowserThread::GetMessageLoopProxyForThread(
+      content::BrowserThread::IO);
+}
+
+}  // namespace engine
+}  // namespace blimp