components: Cleanup class/struct fwd declarations

components/cronet/android/cronet_url_request_adapter.h

 // Copyright 2014 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_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_
 #define COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_
 
 #include <jni.h>
 
 #include <memory>
 #include <string>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "net/base/request_priority.h"
 #include "net/url_request/url_request.h"
 #include "url/gurl.h"
 
-namespace base {
-class SingleThreadTaskRunner;
-}  // namespace base
-
 namespace net {
 class HttpRequestHeaders;
-class HttpResponseHeaders;
 class SSLCertRequestInfo;
 class SSLInfo;
 class UploadDataStream;
 }  // namespace net
 
 namespace cronet {
 
 class CronetURLRequestContextAdapter;
 class IOBufferWithByteBuffer;
 class TestUtil;
@@ skipping 119 matching lines @@
   // Whether detailed metrics should be collected and reported to Java for this
   // request.
   const bool enable_metrics_;
 
   DISALLOW_COPY_AND_ASSIGN(CronetURLRequestAdapter);
 };
 
 }  // namespace cronet
 
 #endif  // COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_ADAPTER_H_