[Cronet] Provide shim from deprecated cronet_c_for_grpc API to bidirectional_stream_c API.

components/cronet/ios/Cronet.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.
 
 #import <Foundation/Foundation.h>
 
 #include "bidirectional_stream_c.h"
 
+// TODO(mef): Remove this header after transition to bidirectional_stream_c.h
+// See crbug.com/650462 for details.
+#include "cronet_c_for_grpc.h"
+
 // A block, that takes a request, and returns YES if the request should
 // be handled.
 typedef BOOL (^RequestFilterBlock)(NSURLRequest* request);
 
 // Interface for installing Cronet.
 // TODO(gcasto): Should this macro be separate from the one defined in
 // bidirectional_stream_c.h?
 GRPC_SUPPORT_EXPORT
 @interface Cronet : NSObject
 
@@ skipping 85 matching lines @@
 
 // Sets Host Resolver Rules for testing.
 // This method must be called after |start| has been called.
 + (void)setHostResolverRulesForTesting:(NSString*)hostResolverRulesForTesting;
 
 // Enables TestCertVerifier which accepts all certificates for testing.
 // This method only has any effect before |start| is called.
 + (void)enableTestCertVerifierForTesting;
 
 @end