change overlay scrollbar hover show to hover fade in

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 e2bf3d4f797e1980dc0d1881cf32043736274d48..9ced3c3d8046fbe093b674d70352f85b249d9af3 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -2870,10 +2870,11 @@ class LayerTreeHostImplTestScrollbarAnimation : public LayerTreeHostImplTest {
   void RunTest(LayerTreeSettings::ScrollbarAnimator animator) {
     LayerTreeSettings settings = DefaultSettings();
     settings.scrollbar_animator = animator;
-    settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(20);
+    settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(20);
     settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(20);
     settings.scrollbar_fade_out_resize_delay =
         base::TimeDelta::FromMilliseconds(20);
+    settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(20);
     settings.scrollbar_fade_out_duration =
         base::TimeDelta::FromMilliseconds(20);
 
@@ -3094,8 +3095,9 @@ class LayerTreeHostImplTestScrollbarOpacity : public LayerTreeHostImplTest {
   void RunTest(LayerTreeSettings::ScrollbarAnimator animator) {
     LayerTreeSettings settings = DefaultSettings();
     settings.scrollbar_animator = animator;
-    settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(20);
+    settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(20);
     settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(20);
+    settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(20);
     settings.scrollbar_fade_out_duration =
         base::TimeDelta::FromMilliseconds(20);
     gfx::Size content_size(100, 100);
@@ -3193,8 +3195,9 @@ TEST_F(LayerTreeHostImplTestScrollbarOpacity, NoAnimator) {
 TEST_F(LayerTreeHostImplTest, ScrollbarVisibilityChangeCausesRedrawAndCommit) {
   LayerTreeSettings settings = DefaultSettings();
   settings.scrollbar_animator = LayerTreeSettings::AURA_OVERLAY;
-  settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(20);
+  settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(20);
   settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(20);
+  settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(20);
   settings.scrollbar_fade_out_duration = base::TimeDelta::FromMilliseconds(20);
   gfx::Size content_size(100, 100);
 
@@ -3232,8 +3235,8 @@ TEST_F(LayerTreeHostImplTest, ScrollbarVisibilityChangeCausesRedrawAndCommit) {
     ASSERT_TRUE(scrollbar_controller->ScrollbarsHidden());
   }
 
-  // Move the mouse over the scrollbar region. This should post a delayed show
-  // task. Execute it to show the scrollbars.
+  // Move the mouse over the scrollbar region. This should post a delayed fade
+  // in task. Execute it to show the scrollbars.
   {
     animation_task_ = base::Closure();
     scrollbar_controller->DidMouseMoveNear(VERTICAL, 0);
@@ -3241,13 +3244,19 @@ TEST_F(LayerTreeHostImplTest, ScrollbarVisibilityChangeCausesRedrawAndCommit) {
     ASSERT_FALSE(animation_task_.IsCancelled());
   }
 
-  // The show task should cause the scrollbars to show. Ensure that we
+  // The fade in task should cause the scrollbars to show. Ensure that we
   // requested a redraw and a commit.
   {
     did_request_redraw_ = false;
     did_request_commit_ = false;
     ASSERT_TRUE(scrollbar_controller->ScrollbarsHidden());
     animation_task_.Run();
+
+    base::TimeTicks fake_now = base::TimeTicks::Now();
+    scrollbar_controller->Animate(fake_now);
+    fake_now += settings.scrollbar_fade_in_duration;
+    scrollbar_controller->Animate(fake_now);
+
     ASSERT_FALSE(scrollbar_controller->ScrollbarsHidden());
     EXPECT_TRUE(did_request_redraw_);
     EXPECT_TRUE(did_request_commit_);
@@ -3291,8 +3300,9 @@ TEST_F(LayerTreeHostImplTest, ScrollbarInnerLargerThanOuter) {
 TEST_F(LayerTreeHostImplTest, ScrollbarRegistration) {
   LayerTreeSettings settings = DefaultSettings();
   settings.scrollbar_animator = LayerTreeSettings::ANDROID_OVERLAY;
-  settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(20);
+  settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(20);
   settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(20);
+  settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(20);
   settings.scrollbar_fade_out_duration = base::TimeDelta::FromMilliseconds(20);
   CreateHostImpl(settings, CreateCompositorFrameSink());
 
@@ -3413,8 +3423,9 @@ TEST_F(LayerTreeHostImplTest, ScrollbarRegistration) {
 void LayerTreeHostImplTest::SetupMouseMoveAtWithDeviceScale(
     float device_scale_factor) {
   LayerTreeSettings settings = DefaultSettings();
-  settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(500);
+  settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(500);
   settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(500);
+  settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(500);
   settings.scrollbar_fade_out_duration = base::TimeDelta::FromMilliseconds(300);
   settings.scrollbar_animator = LayerTreeSettings::AURA_OVERLAY;
 
@@ -12032,8 +12043,9 @@ TEST_F(LayerTreeHostImplTest, RecomputeGpuRasterOnCompositorFrameSinkChange) {
 void LayerTreeHostImplTest::SetupMouseMoveAtTestScrollbarStates(
     bool main_thread_scrolling) {
   LayerTreeSettings settings = DefaultSettings();
-  settings.scrollbar_show_delay = base::TimeDelta::FromMilliseconds(500);
+  settings.scrollbar_fade_in_delay = base::TimeDelta::FromMilliseconds(500);
   settings.scrollbar_fade_out_delay = base::TimeDelta::FromMilliseconds(500);
+  settings.scrollbar_fade_in_duration = base::TimeDelta::FromMilliseconds(500);
   settings.scrollbar_fade_out_duration = base::TimeDelta::FromMilliseconds(300);
   settings.scrollbar_animator = LayerTreeSettings::AURA_OVERLAY;