Add Data Saver support to Cronet

components/cronet/url_request_context_config.h

Index: components/cronet/url_request_context_config.h
diff --git a/components/cronet/url_request_context_config.h b/components/cronet/url_request_context_config.h
index 30530f5d81771a461fddb50a746a0a55d8a4d4b8..afcc734ebb1e93451fa82767fbd7000c484441e6 100644
--- a/components/cronet/url_request_context_config.h
+++ b/components/cronet/url_request_context_config.h
@@ -74,6 +74,11 @@ struct URLRequestContextConfig {
   ScopedVector<QuicHint> quic_hints;
   // Comma-separted list of QUIC connection options.
   std::string quic_connection_options;
+  // Enable Data Reduction Proxy with authentication key.
+  std::string data_reduction_proxy_key;
+  std::string data_reduction_primary_proxy;
+  std::string data_reduction_fallback_proxy;
+  std::string data_reduction_secure_proxy_check_url;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(URLRequestContextConfig);