Add UMA to net::BidirectionalStream

net/http/bidirectional_stream.h

Index: net/http/bidirectional_stream.h
diff --git a/net/http/bidirectional_stream.h b/net/http/bidirectional_stream.h
index 635cf5b795174f8c67baa5b643da2742a65f7b15..d4e121bf20febdec08162a0b1c360390d4af1acf 100644
--- a/net/http/bidirectional_stream.h
+++ b/net/http/bidirectional_stream.h
@@ -19,6 +19,10 @@
 
 class GURL;
 
+namespace base {
+class TickClock;
+}  // namespace base
+
 namespace net {
 
 class HttpAuthController;
@@ -218,6 +222,8 @@ class NET_EXPORT BidirectionalStream
   // Helper method to notify delegate if there is an error.
   void NotifyFailed(int error);
 
+  void UpdateHistograms();
+
   // BidirectionalStreamRequestInfo used when requesting the stream.
   std::unique_ptr<BidirectionalStreamRequestInfo> request_info_;
   const BoundNetLog net_log_;
@@ -248,6 +254,12 @@ class NET_EXPORT BidirectionalStream
   // List of buffer length.
   std::vector<int> write_buffer_len_list_;
 
+  base::TimeTicks start_time_;
+  base::TimeTicks recv_first_byte_time_;
+  base::TimeTicks recv_last_byte_time_;
+
+  std::unique_ptr<base::TickClock> tick_clock_;
+
   base::WeakPtrFactory<BidirectionalStream> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BidirectionalStream);