Add a NetworkQualityEstimator to TestURLRequestContext.

net/http/http_transaction_test_util.h

Index: net/http/http_transaction_test_util.h
diff --git a/net/http/http_transaction_test_util.h b/net/http/http_transaction_test_util.h
index 718fe2727bcd0c7270c08273cfb5879452212ca0..aedadb22d9e4e554edbe0e86c810b31c93c5bf7b 100644
--- a/net/http/http_transaction_test_util.h
+++ b/net/http/http_transaction_test_util.h
@@ -15,6 +15,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
+#include "base/time/time.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_error_details.h"
@@ -280,6 +281,8 @@ class MockNetworkTransaction
 
   bool done_reading_called_;
 
+  base::TimeTicks start_time_;
+
   base::WeakPtrFactory<MockNetworkTransaction> weak_factory_;
 
 };