cc: Disallow scroll offset animations when impl-scrolling isn't supported

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index e00d2c5b905df44584ff21fdb275ae919cffaa25..82978daa03633a23d52b405414b4be0ead50b08c 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -14,6 +14,7 @@
 #include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_events.h"
+#include "cc/animation/animation_registrar.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/layers/layer_client.h"
@@ -1099,6 +1100,11 @@ bool Layer::AddAnimation(scoped_ptr <Animation> animation) {
   if (!layer_animation_controller_->animation_registrar())
     return false;
 
+  if (animation->target_property() == Animation::ScrollOffset &&
+      !layer_animation_controller_->animation_registrar()
+           ->supports_scroll_animations())
+    return false;
+
   UMA_HISTOGRAM_BOOLEAN("Renderer.AnimationAddedToOrphanLayer",
                         !layer_tree_host_);
   layer_animation_controller_->AddAnimation(animation.Pass());