Change the distance trigger scrollbar show

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 c4fda1a43c8331c22fcf7fe807f678215b20f1ef..40b1354af160aa9f654108a54b7cb23a15ed229e 100644
--- a/cc/input/scrollbar_animation_controller_unittest.cc
+++ b/cc/input/scrollbar_animation_controller_unittest.cc
@@ -1042,8 +1042,8 @@ TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
 
   base::Closure& fade = client_.start_fade();
   // Move mouse inside scrollbar. should not post a new show.
-  scrollbar_controller_->DidMouseMoveNear(
-      VERTICAL, kMouseMoveDistanceToTriggerShow - kThumbThickness - 1);
+  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
+                                          kMouseMoveDistanceToTriggerShow - 1);
 
   EXPECT_TRUE(fade.Equals(client_.start_fade()));
 }
@@ -1064,8 +1064,8 @@ TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
   EXPECT_EQ(kShowDelay, client_.delay());
 
   // Move mouse out of scrollbar，delay show should be canceled.
-  scrollbar_controller_->DidMouseMoveNear(
-      VERTICAL, kMouseMoveDistanceToTriggerShow - kThumbThickness);
+  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
+                                          kMouseMoveDistanceToTriggerShow);
   EXPECT_TRUE(client_.start_fade().is_null() ||
               client_.start_fade().IsCancelled());
 }