change overlay scrollbar hover show to hover fade in

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..1dd33d5a6cbf1527fae2a79e23151984346544d3 100644
--- a/cc/input/scrollbar_animation_controller_unittest.cc
+++ b/cc/input/scrollbar_animation_controller_unittest.cc
@@ -26,8 +26,8 @@ const float kIdleThicknessScale =
 const float kDefaultMouseMoveDistanceToTriggerAnimation =
     SingleScrollbarAnimationControllerThinning::
         kDefaultMouseMoveDistanceToTriggerAnimation;
-const float kMouseMoveDistanceToTriggerShow =
-    ScrollbarAnimationController::kMouseMoveDistanceToTriggerShow;
+const float kMouseMoveDistanceToTriggerFadeIn =
+    ScrollbarAnimationController::kMouseMoveDistanceToTriggerFadeIn;
 const int kThumbThickness = 10;
 
 class MockScrollbarAnimationControllerClient
@@ -70,9 +70,10 @@ class ScrollbarAnimationControllerAuraOverlayTest : public testing::Test {
   }
 
  protected:
-  const base::TimeDelta kShowDelay = base::TimeDelta::FromSeconds(4);
+  const base::TimeDelta kFadeInDelay = base::TimeDelta::FromSeconds(4);
   const base::TimeDelta kFadeOutDelay = base::TimeDelta::FromSeconds(2);
   const base::TimeDelta kResizeFadeOutDelay = base::TimeDelta::FromSeconds(5);
+  const base::TimeDelta kFadeInDuration = base::TimeDelta::FromSeconds(3);
   const base::TimeDelta kFadeOutDuration = base::TimeDelta::FromSeconds(3);
   const base::TimeDelta kThinningDuration = base::TimeDelta::FromSeconds(2);
 
@@ -115,8 +116,9 @@ class ScrollbarAnimationControllerAuraOverlayTest : public testing::Test {
 
     scrollbar_controller_ = ScrollbarAnimationController::
         CreateScrollbarAnimationControllerAuraOverlay(
-            scroll_layer_ptr->id(), &client_, kShowDelay, kFadeOutDelay,
-            kResizeFadeOutDelay, kFadeOutDuration, kThinningDuration);
+            scroll_layer_ptr->id(), &client_, kFadeInDelay, kFadeOutDelay,
+            kResizeFadeOutDelay, kFadeInDuration, kFadeOutDuration,
+            kThinningDuration);
   }
 
   FakeImplTaskRunnerProvider task_runner_provider_;
@@ -1006,17 +1008,17 @@ TEST_F(ScrollbarAnimationControllerAuraOverlayTest, MouseLeaveFadeOut) {
   EXPECT_EQ(kFadeOutDelay, client_.delay());
 }
 
-// Scrollbars should schedule a delay show when mouse hover the show scrollbar
-// region of a hidden scrollbar.
-TEST_F(ScrollbarAnimationControllerAuraOverlayTest, BasicMouseHoverShow) {
+// Scrollbars should schedule a delay fade in when mouse hover the show
+// scrollbar region of a hidden scrollbar.
+TEST_F(ScrollbarAnimationControllerAuraOverlayTest, BasicMouseHoverFadeIn) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  // Move mouse hover the show scrollbar region of scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 1);
+  // Move mouse hover the fade in scrollbar region of scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 1);
 
-  // An show animation should have been enqueued.
+  // An fade in animation should have been enqueued.
   EXPECT_FALSE(client_.start_fade().is_null());
   EXPECT_FALSE(client_.start_fade().IsCancelled());
   EXPECT_EQ(kShowDelay, client_.delay());
@@ -1024,83 +1026,95 @@ TEST_F(ScrollbarAnimationControllerAuraOverlayTest, BasicMouseHoverShow) {
   // Play the delay animation.
   client_.start_fade().Run();
   EXPECT_TRUE(client_.start_fade().IsCancelled());
+
+  scrollbar_controller_->Animate(time);
+  time += kFadeInDuration / 2;
+  scrollbar_controller_->Animate(time);
+
+  ExpectScrollbarsOpacity(0.5);
+  EXPECT_FALSE(scrollbar_controller_->ScrollbarsHidden());
+
+  time += kFadeInDuration / 2;
+  scrollbar_controller_->Animate(time);
+
+  ExpectScrollbarsOpacity(1);
   EXPECT_FALSE(scrollbar_controller_->ScrollbarsHidden());
 }
 
-// Scrollbars should not schedule a new delay show when the mouse hovers inside
-// a scrollbar already scheduled a delay show.
+// Scrollbars should not schedule a new delay fade in when the mouse hovers
+// inside a scrollbar already scheduled a delay fade in.
 TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
        MouseHoverScrollbarAndMoveInside) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  // Move mouse hover the show scrollbar region of scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 1);
+  // Move mouse hover the fade in scrollbar region of scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 1);
 
-  // An show animation should have been enqueued.
+  // An fade in animation should have been enqueued.
   EXPECT_FALSE(client_.start_fade().is_null());
   EXPECT_FALSE(client_.start_fade().IsCancelled());
   EXPECT_EQ(kShowDelay, client_.delay());
 
   base::Closure& fade = client_.start_fade();
-  // Move mouse still hover the show scrollbar region of scrollbar should not
-  // post a new show.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 2);
+  // Move mouse still hover the fade in scrollbar region of scrollbar should not
+  // post a new fade in.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 2);
 
   EXPECT_TRUE(fade.Equals(client_.start_fade()));
 }
 
-// Scrollbars should cancel delay show when mouse hover hidden scrollbar then
+// Scrollbars should cancel delay fade in when mouse hover hidden scrollbar then
 // move far away.
 TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
-       MouseHoverThenOutShouldCancelShow) {
+       MouseHoverThenOutShouldCancelFadeIn) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  // Move mouse hover the show scrollbar region of scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 1);
+  // Move mouse hover the fade in scrollbar region of scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 1);
 
-  // An show animation should have been enqueued.
+  // An fade in animation should have been enqueued.
   EXPECT_FALSE(client_.start_fade().is_null());
   EXPECT_FALSE(client_.start_fade().IsCancelled());
   EXPECT_EQ(kShowDelay, client_.delay());
 
-  // Move mouse far away，delay show should be canceled.
+  // Move mouse far away，delay fade in should be canceled.
   scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow);
+                                          kMouseMoveDistanceToTriggerFadeIn);
   EXPECT_TRUE(client_.start_fade().is_null() ||
               client_.start_fade().IsCancelled());
 }
 
-// Scrollbars should cancel delay show when mouse hover hidden scrollbar then
+// Scrollbars should cancel delay fade in when mouse hover hidden scrollbar then
 // move out of window.
 TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
-       MouseHoverThenLeaveShouldCancelShowThenEnterShouldShow) {
+       MouseHoverThenLeaveShouldCancelShowThenEnterShouldFadeIn) {
   base::TimeTicks time;
   time += base::TimeDelta::FromSeconds(1);
 
-  // Move mouse hover the show scrollbar region of scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 1);
+  // Move mouse hover the fade in scrollbar region of scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 1);
 
-  // An show animation should have been enqueued.
+  // An fade in animation should have been enqueued.
   EXPECT_FALSE(client_.start_fade().is_null());
   EXPECT_FALSE(client_.start_fade().IsCancelled());
   EXPECT_EQ(kShowDelay, client_.delay());
 
-  // Move mouse out of window，delay show should be canceled.
+  // Move mouse out of window，delay fade in should be canceled.
   scrollbar_controller_->DidMouseLeave();
   EXPECT_TRUE(client_.start_fade().is_null() ||
               client_.start_fade().IsCancelled());
 
-  // Move mouse hover the show scrollbar region of scrollbar.
-  scrollbar_controller_->DidMouseMoveNear(VERTICAL,
-                                          kMouseMoveDistanceToTriggerShow - 1);
+  // Move mouse hover the fade in scrollbar region of scrollbar.
+  scrollbar_controller_->DidMouseMoveNear(
+      VERTICAL, kMouseMoveDistanceToTriggerFadeIn - 1);
 
-  // An show animation should have been enqueued.
+  // An fade in animation should have been enqueued.
   EXPECT_FALSE(client_.start_fade().is_null());
   EXPECT_FALSE(client_.start_fade().IsCancelled());
   EXPECT_EQ(kShowDelay, client_.delay());
@@ -1108,6 +1122,11 @@ TEST_F(ScrollbarAnimationControllerAuraOverlayTest,
   // Play the delay animation.
   client_.start_fade().Run();
   EXPECT_TRUE(client_.start_fade().IsCancelled());
+
+  scrollbar_controller_->Animate(time);
+  time += kFadeInDuration;
+  scrollbar_controller_->Animate(time);
+
   EXPECT_FALSE(scrollbar_controller_->ScrollbarsHidden());
 }