google_apis: Migrate callers of message_loop_proxy() to task_runner()

google_apis/gaia/account_tracker_unittest.cc

Index: google_apis/gaia/account_tracker_unittest.cc
diff --git a/google_apis/gaia/account_tracker_unittest.cc b/google_apis/gaia/account_tracker_unittest.cc
index 532ed355595e8f640fbe8c6aece4518f5c58ef52..61fded91a1ad6689022140f189ad7fc5b4a990b4 100644
--- a/google_apis/gaia/account_tracker_unittest.cc
+++ b/google_apis/gaia/account_tracker_unittest.cc
@@ -275,7 +275,7 @@ class IdentityAccountTrackerTest : public testing::Test {
     account_tracker_.reset(
         new AccountTracker(fake_identity_provider_.get(),
                            new net::TestURLRequestContextGetter(
-                               message_loop_.message_loop_proxy())));
+                               message_loop_.task_runner())));
     account_tracker_->AddObserver(&observer_);
   }