cc : Delete LayerImpl::OnOpacityAnimated

cc/input/scrollbar_animation_controller_linear_fade.cc

Index: cc/input/scrollbar_animation_controller_linear_fade.cc
diff --git a/cc/input/scrollbar_animation_controller_linear_fade.cc b/cc/input/scrollbar_animation_controller_linear_fade.cc
index 8ead32491a3f9eebd4ccc55b1bdb3f77ab04cf89..56fd2d1eeba5f2628c02a7a0caeb9000cdbeccd3 100644
--- a/cc/input/scrollbar_animation_controller_linear_fade.cc
+++ b/cc/input/scrollbar_animation_controller_linear_fade.cc
@@ -8,6 +8,7 @@
 #include "base/time/time.h"
 #include "cc/layers/layer_impl.h"
 #include "cc/layers/scrollbar_layer_impl_base.h"
+#include "cc/trees/layer_tree_impl.h"
 
 namespace cc {
 
@@ -55,8 +56,15 @@ void ScrollbarAnimationControllerLinearFade::ApplyOpacityToScrollbars(
   for (ScrollbarLayerImplBase* scrollbar : Scrollbars()) {
     if (!scrollbar->is_overlay_scrollbar())
       continue;
-    scrollbar->OnOpacityAnimated(scrollbar->CanScrollOrientation() ? opacity
-                                                                   : 0);
+    PropertyTrees* property_trees =
+        scrollbar->layer_tree_impl()->property_trees();
+    if (property_trees->IsInIdToIndexMap(PropertyTrees::TreeType::EFFECT,
+                                         scrollbar->id())) {
+      property_trees->effect_tree.OnOpacityAnimated(
+          scrollbar->CanScrollOrientation() ? opacity : 0,
+          property_trees->effect_id_to_index_map[scrollbar->id()],
+          scrollbar->layer_tree_impl());
+    }

[jaydasika, 2016/08/23 23:12:01]

OnOpacityAnimated can be called during layer's PushPropertiesTo for scrollbars
(PushProperties -> RegisterScrollbar-> updateScrollbar ->
ApplyopacityToScrollbar -> OnOpacityAnimated), but during activation we
implicitly overwrite this value because we push property trees after we push
layer properties. So, here, I first check if the scrollbar's id is in effect
tree's id_to_index_map. If it isn't => the call is happening during
PushPropertiesTo and we don't have to update opacity.

[ajuma, 2016/08/23 23:48:16]

Please add a comment about this.

[jaydasika, 2016/08/24 00:37:46]

Done.

   }
 }