Iframe/div MD scrollbars get idle when mouse leaves the nested elements.

cc/input/scrollbar_animation_controller_thinning_unittest.cc

Index: cc/input/scrollbar_animation_controller_thinning_unittest.cc
diff --git a/cc/input/scrollbar_animation_controller_thinning_unittest.cc b/cc/input/scrollbar_animation_controller_thinning_unittest.cc
index 64096b7eae0e9581e152ef81d1602125be795b59..928a2b08a713d54b8d8daefd5e46901fdd2d2046 100644
--- a/cc/input/scrollbar_animation_controller_thinning_unittest.cc
+++ b/cc/input/scrollbar_animation_controller_thinning_unittest.cc
@@ -428,7 +428,7 @@ TEST_F(ScrollbarAnimationControllerThinningTest,
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Capture
-  scrollbar_controller_->DidCaptureScrollbarBegin();
+  scrollbar_controller_->DidMouseDown();
   time += base::TimeDelta::FromSeconds(1);
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
@@ -445,7 +445,7 @@ TEST_F(ScrollbarAnimationControllerThinningTest,
   }
 
   // release
-  scrollbar_controller_->DidCaptureScrollbarEnd();
+  scrollbar_controller_->DidMouseUp();
 
   // get thickness and light
   time += base::TimeDelta::FromSeconds(1);
@@ -486,7 +486,7 @@ TEST_F(ScrollbarAnimationControllerThinningTest, MouseCaptureAndReleaseOnBar) {
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Capture
-  scrollbar_controller_->DidCaptureScrollbarBegin();
+  scrollbar_controller_->DidMouseDown();
   time += base::TimeDelta::FromSeconds(1);
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
@@ -506,7 +506,7 @@ TEST_F(ScrollbarAnimationControllerThinningTest, MouseCaptureAndReleaseOnBar) {
   scrollbar_controller_->DidMouseMoveNear(0);
 
   // release
-  scrollbar_controller_->DidCaptureScrollbarEnd();
+  scrollbar_controller_->DidMouseUp();
 
   // stay thick and dark
   // test for 10 seconds, stay thick and dark
@@ -535,7 +535,7 @@ TEST_F(ScrollbarAnimationControllerThinningTest,
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 
   // Capture
-  scrollbar_controller_->DidCaptureScrollbarBegin();
+  scrollbar_controller_->DidMouseDown();
   time += base::TimeDelta::FromSeconds(1);
   scrollbar_controller_->Animate(time);
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());