Merge Compositor's ScrollbarAnimationControllers into single class

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 2b0b9676be86849168b31c3ef7cc88a170d719bf..4e7ea0141833325e60a70f7cbbaee4d206b0f853 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -22,7 +22,6 @@
 #include "cc/input/browser_controls_offset_manager.h"
 #include "cc/input/main_thread_scrolling_reason.h"
 #include "cc/input/page_scale_animation.h"
-#include "cc/input/scrollbar_animation_controller_thinning.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/heads_up_display_layer_impl.h"
 #include "cc/layers/layer_impl.h"
@@ -3194,9 +3193,8 @@ void LayerTreeHostImplTest::SetupMouseMoveAtWithDeviceScale(
   DrawFrame();
   host_impl_->active_tree()->UpdateDrawProperties(false);
 
-  ScrollbarAnimationControllerThinning* scrollbar_animation_controller =
-      static_cast<ScrollbarAnimationControllerThinning*>(
-          host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
+  ScrollbarAnimationController* scrollbar_animation_controller =
+          host_impl_->ScrollbarAnimationControllerForId(root_scroll->id());
   scrollbar_animation_controller->set_mouse_move_distance_for_test(100.f);
 
   host_impl_->MouseMoveAt(gfx::Point(200, 1));
@@ -11609,9 +11607,8 @@ void LayerTreeHostImplTest::SetupMouseMoveAtTestScrollbarStates(
   DrawFrame();
   host_impl_->active_tree()->UpdateDrawProperties(false);
 
-  ScrollbarAnimationControllerThinning* scrollbar_1_animation_controller =
-      static_cast<ScrollbarAnimationControllerThinning*>(
-          host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
+  ScrollbarAnimationController* scrollbar_1_animation_controller =
+          host_impl_->ScrollbarAnimationControllerForId(root_scroll->id());
   EXPECT_TRUE(scrollbar_1_animation_controller);
   scrollbar_1_animation_controller->set_mouse_move_distance_for_test(40.f);
 
@@ -11673,9 +11670,8 @@ void LayerTreeHostImplTest::SetupMouseMoveAtTestScrollbarStates(
   host_impl_->active_tree()->BuildPropertyTreesForTesting();
   host_impl_->active_tree()->DidBecomeActive();
 
-  ScrollbarAnimationControllerThinning* scrollbar_2_animation_controller =
-      static_cast<ScrollbarAnimationControllerThinning*>(
-          host_impl_->ScrollbarAnimationControllerForId(child_scroll_id));
+  ScrollbarAnimationController* scrollbar_2_animation_controller =
+          host_impl_->ScrollbarAnimationControllerForId(child_scroll_id);
   EXPECT_TRUE(scrollbar_2_animation_controller);
   scrollbar_2_animation_controller->set_mouse_move_distance_for_test(40.f);