Replace layer id with Element id for tracking scrollbar animation controllers

cc/input/scrollbar_animation_controller_unittest.cc

Index: cc/input/scrollbar_animation_controller_unittest.cc
diff --git a/cc/input/scrollbar_animation_controller_unittest.cc b/cc/input/scrollbar_animation_controller_unittest.cc
index ead11c253f6c5507793f2c8ad8bec459f424bb75..76026013c34c452b9e90fff0ccde6990a38f1aa0 100644
--- a/cc/input/scrollbar_animation_controller_unittest.cc
+++ b/cc/input/scrollbar_animation_controller_unittest.cc
@@ -105,8 +105,10 @@ class ScrollbarAnimationControllerAuraOverlayTest : public testing::Test {
     clip_layer_->test_properties()->AddChild(std::move(scroll_layer));
     host_impl_.active_tree()->SetRootLayerForTesting(std::move(clip));
 
-    v_scrollbar_layer_->SetScrollLayerId(scroll_layer_ptr->id());
-    h_scrollbar_layer_->SetScrollLayerId(scroll_layer_ptr->id());
+    v_scrollbar_layer_->SetScrollInfo(scroll_layer_ptr->id(),
+                                      scroll_layer_ptr->element_id());
+    h_scrollbar_layer_->SetScrollInfo(scroll_layer_ptr->id(),
+                                      scroll_layer_ptr->element_id());
     v_scrollbar_layer_->test_properties()->opacity_can_animate = true;
     h_scrollbar_layer_->test_properties()->opacity_can_animate = true;
     clip_layer_->SetBounds(gfx::Size(100, 100));
@@ -1159,7 +1161,8 @@ class ScrollbarAnimationControllerAndroidTest
     clip->test_properties()->AddChild(std::move(scroll_layer));
     host_impl_.active_tree()->SetRootLayerForTesting(std::move(clip));
 
-    scrollbar_layer_->SetScrollLayerId(scroll_layer_ptr->id());
+    scrollbar_layer_->SetScrollInfo(scroll_layer_ptr->id(),
+                                    scroll_layer_ptr->element_id());
     clip_layer_->SetBounds(gfx::Size(100, 100));
     scroll_layer_ptr->SetBounds(gfx::Size(200, 200));
     host_impl_.active_tree()->BuildLayerListAndPropertyTreesForTesting();