Fix unused variables errors in cc/.

cc/test/animation_timelines_test_common.cc

Index: cc/test/animation_timelines_test_common.cc
diff --git a/cc/test/animation_timelines_test_common.cc b/cc/test/animation_timelines_test_common.cc
index ea9d0b00cd65295a9f537d8370af5b1b8e49bd0a..c5491f88a8a1cb7a5db03a0d9170f1d6b1c5e82e 100644
--- a/cc/test/animation_timelines_test_common.cc
+++ b/cc/test/animation_timelines_test_common.cc
@@ -35,9 +35,8 @@ void TestLayer::ClearMutatedProperties() {
     mutated_properties_[i] = false;
 }
 
-TestHostClient::TestHostClient(ThreadInstance thread_instance)
-    : host_(AnimationHost::Create(thread_instance)),
-      mutators_need_commit_(false) {
+TestHostClient::TestHostClient()
+    : host_(AnimationHost::Create()), mutators_need_commit_(false) {
   host_->SetMutatorHostClient(this);
 }
 
@@ -193,8 +192,8 @@ void TestAnimationDelegate::NotifyAnimationFinished(
 }
 
 AnimationTimelinesTest::AnimationTimelinesTest()
-    : client_(ThreadInstance::MAIN),
-      client_impl_(ThreadInstance::IMPL),
+    : client_(),

[vmpstr, 2015/07/06 20:00:41]

nit: You can remove these two lines now.

[mlamouri (slow - plz ping), 2015/07/06 20:10:55]

Done.

+      client_impl_(),
       timeline_id_(AnimationIdProvider::NextTimelineId()),
       player_id_(AnimationIdProvider::NextPlayerId()),
       layer_id_(1) {