Keep expanded if mouse moves off of scrollbar while dragging

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 e1a1aa3cd53a5b79aafd9cd8c544d86f539232cf..90090b1fa69e30d7b20cec2a5a56bd0cb80895af 100644
--- a/cc/input/scrollbar_animation_controller_thinning_unittest.cc
+++ b/cc/input/scrollbar_animation_controller_thinning_unittest.cc
@@ -55,6 +55,13 @@ class ScrollbarAnimationControllerThinningTest
     const int kTrackStart = 0;
     const bool kIsLeftSideVerticalScrollbar = false;
     const bool kIsOverlayScrollbar = true;
+
+    const base::TimeDelta delay_before_starting
+          = base::TimeDelta::FromSeconds(2);
+    const base::TimeDelta resize_delay_before_starting
+          = base::TimeDelta::FromSeconds(5);
+    const base::TimeDelta duration = base::TimeDelta::FromSeconds(3);
+
     std::unique_ptr<SolidColorScrollbarLayerImpl> scrollbar =
         SolidColorScrollbarLayerImpl::Create(
             host_impl_.active_tree(), kId, HORIZONTAL, kThumbThickness,
@@ -72,8 +79,8 @@ class ScrollbarAnimationControllerThinningTest
     host_impl_.active_tree()->BuildLayerListAndPropertyTreesForTesting();
 
     scrollbar_controller_ = ScrollbarAnimationControllerThinning::Create(
-        scroll_layer_ptr->id(), this, base::TimeDelta::FromSeconds(2),
-        base::TimeDelta::FromSeconds(5), base::TimeDelta::FromSeconds(3));
+        scroll_layer_ptr->id(), this, delay_before_starting,
+        resize_delay_before_starting, duration);
   }
 
   FakeImplTaskRunnerProvider task_runner_provider_;
@@ -386,5 +393,117 @@ TEST_F(ScrollbarAnimationControllerThinningTest, MouseNearThenOver) {
   EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
 }
 
+// First move the pointer on the scrollbar, then press it, then away.
+// Confirm that the bar gets thick and dark. Then mouse up. Confirm that
+// the bar gets thin and light.
+TEST_F(ScrollbarAnimationControllerThinningTest,
+       MouseCaptureAndReleaseOutOfBar) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);

[bokan, 2016/09/23 20:21:29]

This should be unneeded, right? Without it we'd just start from time == 0 (0
being different from last_awaken_time_ == nullptr)

[chaopeng, 2016/09/23 20:26:47]

No. It isnot checking nullptr, it is checking is it 0.
https://cs.chromium.org/chromium/src/base/time/time.h?type=cs&sq=package:chro...

[bokan, 2016/09/23 20:30:08]

Ugh, my bad, you're right. That's confusing. Ok, feel free to disregard this
comment and the one below about the comment being wrong.

+
+  // Move in
+  scrollbar_controller_->DidMouseMoveNear(0);
+
+  // Jump X seconds, first we need to make the time not 0, second we need to

[bokan, 2016/09/23 20:21:29]

This isn't quite right. We're making the time not nullptr, 0 should be fine. I'd
replace this comment with "First Animate call is needed to initialize the start
time" or something similar.

+  // call Animate once to start the animation(initial the last_awaken_time_),
+  // now you can jump x seconds.
+  scrollbar_controller_->Animate(time);
+  time += base::TimeDelta::FromSeconds(4);

[bokan, 2016/09/23 20:21:28]

I meant you should use the constant here (this should work with 3 I think). So
make the duration const a class member and use it here.

+  scrollbar_controller_->Animate(time);
+
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Capture
+  scrollbar_controller_->DidCaptureScrollbarBegin();
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // test for 10 seconds, stay thick and dark
+  for (int i = 0; i < 10; ++i) {
+    // move away from bar.
+    scrollbar_controller_->DidMouseMoveNear(26 + i);
+    time += base::TimeDelta::FromSeconds(1);
+    scrollbar_controller_->Animate(time);
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+  }
+
+  // release
+  scrollbar_controller_->DidCaptureScrollbarEnd();
+
+  // get thickness and light
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(0.9f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(0.8f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(0.8f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(0.6f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(0.7f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(0.4f, scrollbar_layer_->thumb_thickness_scale_factor());
+}
+
+// First move the pointer on the scrollbar, then press it, then away.
+// Confirm that the bar gets thick and dark. Then move point on the
+// scrollbar and mouse up. Confirm that the bar gets thick and dark.
+TEST_F(ScrollbarAnimationControllerThinningTest, MouseCaptureAndReleaseOnBar) {
+  base::TimeTicks time;
+  time += base::TimeDelta::FromSeconds(1);
+
+  // Move in
+  scrollbar_controller_->DidMouseMoveNear(0);
+
+  scrollbar_controller_->Animate(time);
+  time += base::TimeDelta::FromSeconds(4);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // Capture
+  scrollbar_controller_->DidCaptureScrollbarBegin();
+  time += base::TimeDelta::FromSeconds(1);
+  scrollbar_controller_->Animate(time);
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+  EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+
+  // test for 10 seconds, stay thick and dark
+  for (int i = 0; i < 10; ++i) {
+    // move away from bar.
+    scrollbar_controller_->DidMouseMoveNear(26 + i);
+    time += base::TimeDelta::FromSeconds(1);
+    scrollbar_controller_->Animate(time);
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+  }
+
+  // move to the bar.
+  scrollbar_controller_->DidMouseMoveNear(0);
+
+  // release
+  scrollbar_controller_->DidCaptureScrollbarEnd();
+
+  // stay thick and dark
+  // test for 10 seconds, stay thick and dark
+  for (int i = 0; i < 10; ++i) {
+    time += base::TimeDelta::FromSeconds(1);
+    scrollbar_controller_->Animate(time);
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->Opacity());
+    EXPECT_FLOAT_EQ(1.0f, scrollbar_layer_->thumb_thickness_scale_factor());
+  }
+}
+
 }  // namespace
 }  // namespace cc