Migrate callers of message_loop_proxy() to task_runner()

jingle/notifier/listener/push_client_unittest.cc

Index: jingle/notifier/listener/push_client_unittest.cc
diff --git a/jingle/notifier/listener/push_client_unittest.cc b/jingle/notifier/listener/push_client_unittest.cc
index 5296663d3cf5e18ac9b9e70dc380f228ef6dab58..1bf4e65329387134348bf01ca1295c570cc2111d 100644
--- a/jingle/notifier/listener/push_client_unittest.cc
+++ b/jingle/notifier/listener/push_client_unittest.cc
@@ -23,7 +23,7 @@ class PushClientTest : public testing::Test {
   PushClientTest() {
     notifier_options_.request_context_getter =
         new net::TestURLRequestContextGetter(
-            message_loop_.message_loop_proxy());
+            message_loop_.task_runner());
   }
 
   ~PushClientTest() override {}