CC: Add fill mode to compositor animations

cc/animation/layer_animation_controller.cc

Index: cc/animation/layer_animation_controller.cc
diff --git a/cc/animation/layer_animation_controller.cc b/cc/animation/layer_animation_controller.cc
index fbd02f38be914b2bdbd652e1e823aa00d7a04888..83ace4f88fcb1496d612ba39c28ee7a3b7e82037 100644
--- a/cc/animation/layer_animation_controller.cc
+++ b/cc/animation/layer_animation_controller.cc
@@ -144,6 +144,9 @@ void LayerAnimationController::AccumulatePropertyUpdates(
     if (!animation->is_impl_only())
       continue;
 
+    if (animation->NoEffectBeforeAnimation(monotonic_time))
+      continue;
+
     double trimmed = animation->TrimTimeToCurrentIteration(monotonic_time);
     switch (animation->target_property()) {
       case Animation::Opacity: {
@@ -835,6 +838,9 @@ void LayerAnimationController::TickAnimations(base::TimeTicks monotonic_time) {
     if (animations_[i]->run_state() == Animation::Starting ||
         animations_[i]->run_state() == Animation::Running ||
         animations_[i]->run_state() == Animation::Paused) {
+      if (animations_[i]->NoEffectBeforeAnimation(monotonic_time))
+        continue;
+
       double trimmed =
           animations_[i]->TrimTimeToCurrentIteration(monotonic_time);