Fix unused variables errors in cc/.

cc/animation/animation_timeline_unittest.cc

Index: cc/animation/animation_timeline_unittest.cc
diff --git a/cc/animation/animation_timeline_unittest.cc b/cc/animation/animation_timeline_unittest.cc
index 3b0bc5ab7301b923b71f7d2e20e64c296af37982..a4b66201801d1bb4a37077415560d860ac555382 100644
--- a/cc/animation/animation_timeline_unittest.cc
+++ b/cc/animation/animation_timeline_unittest.cc
@@ -15,9 +15,8 @@ namespace cc {
 namespace {
 
 TEST(AnimationTimelineTest, SyncPlayersAttachDetach) {
-  scoped_ptr<AnimationHost> host(AnimationHost::Create(ThreadInstance::MAIN));
-  scoped_ptr<AnimationHost> host_impl(
-      AnimationHost::Create(ThreadInstance::IMPL));
+  scoped_ptr<AnimationHost> host(AnimationHost::Create());
+  scoped_ptr<AnimationHost> host_impl(AnimationHost::Create());
 
   const int timeline_id = AnimationIdProvider::NextTimelineId();
   const int player_id = AnimationIdProvider::NextPlayerId();
@@ -60,9 +59,8 @@ TEST(AnimationTimelineTest, SyncPlayersAttachDetach) {
 }
 
 TEST(AnimationTimelineTest, ClearPlayers) {
-  scoped_ptr<AnimationHost> host(AnimationHost::Create(ThreadInstance::MAIN));
-  scoped_ptr<AnimationHost> host_impl(
-      AnimationHost::Create(ThreadInstance::IMPL));
+  scoped_ptr<AnimationHost> host(AnimationHost::Create());
+  scoped_ptr<AnimationHost> host_impl(AnimationHost::Create());
 
   const int timeline_id = AnimationIdProvider::NextTimelineId();
   const int player_id1 = AnimationIdProvider::NextPlayerId();