Smooth scroll animation should not override scroll anchoring update (MT)

third_party/WebKit/Source/platform/scroll/ScrollAnimatorTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 439 matching lines @@
 {
     MockScrollableArea* scrollableArea = MockScrollableArea::create(true);
     TestScrollAnimator* scrollAnimator = new TestScrollAnimator(scrollableArea, getMockedTime);
 
     EXPECT_CALL(*scrollableArea, minimumScrollPosition()).Times(AtLeast(1))
         .WillRepeatedly(Return(IntPoint()));
     EXPECT_CALL(*scrollableArea, maximumScrollPosition()).Times(AtLeast(1))
         .WillRepeatedly(Return(IntPoint(1000, 1000)));
     // Called when reset, not setting anywhere else.
     EXPECT_CALL(*scrollableArea, setScrollOffset(_, _)).Times(1);
-    // Called from first and last user scroll, and first update.
-    EXPECT_CALL(*scrollableArea, registerForAnimation()).Times(3);
+    // Called from userScroll, and first update.
+    EXPECT_CALL(*scrollableArea, registerForAnimation()).Times(4);
     EXPECT_CALL(*scrollableArea, scheduleAnimation()).Times(AtLeast(1))
         .WillRepeatedly(Return(true));
 
     EXPECT_FALSE(scrollAnimator->hasAnimationThatRequiresService());
 
     // First user scroll.
     ScrollResult result = scrollAnimator->userScroll(ScrollByLine, FloatSize(100, 0));
     EXPECT_TRUE(scrollAnimator->hasAnimationThatRequiresService());
     EXPECT_TRUE(result.didScrollX);
     EXPECT_FLOAT_EQ(0.0, result.unusedScrollDeltaX);
     EXPECT_TRUE(scrollAnimator->hasRunningAnimation());
     EXPECT_EQ(100, scrollAnimator->desiredTargetPosition().x());
     EXPECT_EQ(0, scrollAnimator->desiredTargetPosition().y());
 
     // Update compositor animation.
     gMockedTime += 0.05;
     scrollAnimator->setShouldSendToCompositor(true);
     scrollAnimator->updateCompositorAnimations();
     EXPECT_EQ(scrollAnimator->m_runState,
         ScrollAnimatorCompositorCoordinator::RunState::RunningOnCompositor);
 
     // Cancel
     scrollAnimator->cancelAnimation();
     EXPECT_EQ(scrollAnimator->m_runState,
         ScrollAnimatorCompositorCoordinator::RunState::WaitingToCancelOnCompositor);
 
-    // Second user scroll should not affect the run state.
+    // Unrelated scroll position update.
+    scrollAnimator->setCurrentPosition(FloatPoint(50, 0));
+
+    // Desired target position should be that of the second scroll.
     result = scrollAnimator->userScroll(ScrollByLine, FloatSize(100, 0));
     EXPECT_TRUE(scrollAnimator->hasAnimationThatRequiresService());
     EXPECT_TRUE(result.didScrollX);
     EXPECT_FLOAT_EQ(0.0, result.unusedScrollDeltaX);
     EXPECT_EQ(scrollAnimator->m_runState,
-        ScrollAnimatorCompositorCoordinator::RunState::WaitingToCancelOnCompositor);
-    // Desired target position is what it was before.
-    EXPECT_EQ(100, scrollAnimator->desiredTargetPosition().x());
+        ScrollAnimatorCompositorCoordinator::RunState::WaitingToCancelOnCompositorButNewScroll);
+    EXPECT_EQ(150, scrollAnimator->desiredTargetPosition().x());
     EXPECT_EQ(0, scrollAnimator->desiredTargetPosition().y());
 
     // Update compositor animation.
     gMockedTime += 0.05;
     scrollAnimator->updateCompositorAnimations();
     EXPECT_EQ(scrollAnimator->m_runState,
-        ScrollAnimatorCompositorCoordinator::RunState::Idle);
+        ScrollAnimatorCompositorCoordinator::RunState::RunningOnCompositor);
 
-    // Third user scroll after compositor update is treated like a new scroll.
+    // Third user scroll after compositor update updates the target.
     result = scrollAnimator->userScroll(ScrollByLine, FloatSize(100, 0));
     EXPECT_TRUE(scrollAnimator->hasAnimationThatRequiresService());
     EXPECT_TRUE(result.didScrollX);
     EXPECT_FLOAT_EQ(0.0, result.unusedScrollDeltaX);
     EXPECT_EQ(scrollAnimator->m_runState,
-        ScrollAnimatorCompositorCoordinator::RunState::WaitingToSendToCompositor);
-    EXPECT_EQ(100, scrollAnimator->desiredTargetPosition().x());
+        ScrollAnimatorCompositorCoordinator::RunState::RunningOnCompositorButNeedsUpdate);
+    EXPECT_EQ(250, scrollAnimator->desiredTargetPosition().x());
     EXPECT_EQ(0, scrollAnimator->desiredTargetPosition().y());
     reset(*scrollAnimator);
 
     // Forced GC in order to finalize objects depending on the mock object.
     ThreadHeap::collectAllGarbage();
 }
 
 } // namespace blink