Pinch/Zoom Infrastructure & Plumbing CL

cc/animation/scrollbar_animation_controller_thinning.cc

Index: cc/animation/scrollbar_animation_controller_thinning.cc
diff --git a/cc/animation/scrollbar_animation_controller_thinning.cc b/cc/animation/scrollbar_animation_controller_thinning.cc
index ce196fbf955e61320af9a5669f011ced1437f185..0eb972a82208fcd941b6628b48ed7e87722556ad 100644
--- a/cc/animation/scrollbar_animation_controller_thinning.cc
+++ b/cc/animation/scrollbar_animation_controller_thinning.cc
@@ -138,19 +138,18 @@ ScrollbarAnimationControllerThinning::ThumbThicknessScaleAtAnimationProgress(
 
 void ScrollbarAnimationControllerThinning::ApplyOpacityAndThumbThicknessScale(
     float opacity, float thumb_thickness_scale) {
-  ScrollbarLayerImplBase* horizontal_scrollbar =
-      scroll_layer_->horizontal_scrollbar_layer();
-  if (horizontal_scrollbar) {
-    horizontal_scrollbar->SetOpacity(opacity);
-    horizontal_scrollbar->set_thumb_thickness_scale_factor(
-        thumb_thickness_scale);
-  }
-
-  ScrollbarLayerImplBase* vertical_scrollbar =
-      scroll_layer_->vertical_scrollbar_layer();
-  if (vertical_scrollbar) {
-    vertical_scrollbar->SetOpacity(opacity);
-    vertical_scrollbar->set_thumb_thickness_scale_factor(thumb_thickness_scale);
+  if (!scroll_layer_->scrollbars())
+    return;
+
+  LayerImpl::ScrollbarSet* scrollbars = scroll_layer_->scrollbars();
+  for (LayerImpl::ScrollbarSet::iterator it = scrollbars->begin();
+       it != scrollbars->end();
+       ++it) {
+    ScrollbarLayerImplBase* scrollbar = *it;
+    if (scrollbar->opacity_can_animate()) {
+      scrollbar->SetOpacity(opacity);
+      scrollbar->set_thumb_thickness_scale_factor(thumb_thickness_scale);
+    }
   }
 }