Delete message loops from gcm unit tests.

components/gcm_driver/instance_id/instance_id_driver_unittest.cc

Index: components/gcm_driver/instance_id/instance_id_driver_unittest.cc
diff --git a/components/gcm_driver/instance_id/instance_id_driver_unittest.cc b/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
index 9474d2462ab5d91598a17c64425427b4651d5c5d..e4ed6ab2ffa2bbf6dc2dbf63b1ee51098417271d 100644
--- a/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
+++ b/components/gcm_driver/instance_id/instance_id_driver_unittest.cc
@@ -6,7 +6,6 @@
 
 #include <cmath>
 #include "base/bind.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h"
@@ -77,7 +76,6 @@ class InstanceIDDriverTest : public testing::Test {
   void GetTokenCompleted(const std::string& token, InstanceID::Result result);
   void DeleteTokenCompleted(InstanceID::Result result);
 
-  base::MessageLoopForUI message_loop_;
   scoped_ptr<FakeGCMDriverForInstanceID> gcm_driver_;
   scoped_ptr<InstanceIDDriver> driver_;