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

components/cronet/ios/test/get_stream_engine.mm

Index: components/cronet/ios/test/get_stream_engine.mm
diff --git a/components/cronet/ios/test/get_stream_engine.mm b/components/cronet/ios/test/get_stream_engine.mm
deleted file mode 100644
index e82ac79c3b37df0f6f5ea67901b37547f08a6f96..0000000000000000000000000000000000000000
--- a/components/cronet/ios/test/get_stream_engine.mm
+++ /dev/null
@@ -1,18 +0,0 @@
-// 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.
-
-#import <Cronet/Cronet.h>
-#import <Foundation/Foundation.h>
-
-#include "components/cronet/ios/test/start_cronet.h"
-#include "components/grpc_support/test/get_stream_engine.h"
-
-namespace grpc_support {
-
-stream_engine* GetTestStreamEngine() {
-  cronet::StartCronetIfNecessary();
-  return [Cronet getGlobalEngine];
-}
-
-}  // namespace grpc_support