Add missing using declarations in cronet code.

components/cronet/android/cronet_bidirectional_stream_adapter.cc

 // Copyright 2015 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 "cronet_bidirectional_stream_adapter.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 14 matching lines @@
 #include "net/http/http_util.h"
 #include "net/quic/core/quic_protocol.h"
 #include "net/spdy/spdy_header_block.h"
 #include "net/ssl/ssl_info.h"
 #include "net/url_request/http_user_agent_settings.h"
 #include "net/url_request/url_request_context.h"
 #include "url/gurl.h"
 
 using base::android::ConvertUTF8ToJavaString;
 using base::android::ConvertJavaStringToUTF8;
+using base::android::ScopedJavaLocalRef;
 
 namespace cronet {
 
 namespace {
 
 // As |GetArrayLength| makes no guarantees about the returned value (e.g., it
 // may be -1 if |array| is not a valid Java array), provide a safe wrapper
 // that always returns a valid, non-negative size.
 template <typename JavaArrayType>
 size_t SafeGetArrayLength(JNIEnv* env, JavaArrayType jarray) {
@@ skipping 376 matching lines @@
 
   std::vector<std::string> headers;
   for (const auto& header : header_block) {
     headers.push_back(header.first.as_string());
     headers.push_back(header.second.as_string());
   }
   return base::android::ToJavaArrayOfStrings(env, headers);
 }
 
 }  // namespace cronet