Moving gRPC support interfaces out of cronet and into a new component.

components/grpc_support/test/get_stream_engine.h

+// 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.
+
+#ifndef COMPONENTS_GRPC_SUPPORT_TEST_GET_REQUEST_CONTEXT_GETTER_H_
+#define COMPONENTS_GRPC_SUPPORT_TEST_GET_REQUEST_CONTEXT_GETTER_H_
+
+struct stream_engine;
+
+namespace grpc_support {
+
+// Returns a stream_engine* for testing with the QuicTestServer.
+// The engine returned should resolve kTestServerDomain as localhost,
+// and should have kTestServerHost configured as a QUIC server.
+stream_engine* GetTestStreamEngine();
+
+}  // namespace grpc_support
+
+#endif  // COMPONENTS_GRPC_SUPPORT_TEST_GET_REQUEST_CONTEXT_GETTER_H_