Fix double ripple on activated flood fill ripple

ui/views/animation/flood_fill_ink_drop_ripple.cc

Index: ui/views/animation/flood_fill_ink_drop_ripple.cc
diff --git a/ui/views/animation/flood_fill_ink_drop_ripple.cc b/ui/views/animation/flood_fill_ink_drop_ripple.cc
index 10459d8c956d81588dbb6497b2631fd6b9415ffe..5ed22814c1b497d876ddb939af4ca9d8f588e13c 100644
--- a/ui/views/animation/flood_fill_ink_drop_ripple.cc
+++ b/ui/views/animation/flood_fill_ink_drop_ripple.cc
@@ -215,11 +215,10 @@ void FloodFillInkDropRipple::AnimateStateChange(
                        GetAnimationDuration(ACTION_PENDING_FADE_IN),
                        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
                        gfx::Tween::EASE_IN, animation_observer);
-      AnimateToOpacity(visible_opacity_,
-                       GetAnimationDuration(ACTION_PENDING_TRANSFORM) -
-                           GetAnimationDuration(ACTION_PENDING_FADE_IN),
-                       ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
-                       gfx::Tween::EASE_IN, animation_observer);
+      PauseOpacityAnimation(GetAnimationDuration(ACTION_PENDING_TRANSFORM) -
+                                GetAnimationDuration(ACTION_PENDING_FADE_IN),
+                            ui::LayerAnimator::ENQUEUE_NEW_ANIMATION,
+                            animation_observer);
 
       AnimateToTransform(GetMaxSizeTargetTransform(),
                          GetAnimationDuration(ACTION_PENDING_TRANSFORM),
@@ -260,14 +259,28 @@ void FloodFillInkDropRipple::AnimateStateChange(
                        gfx::Tween::EASE_IN_OUT, animation_observer);
       break;
     case InkDropState::ACTIVATED: {
-      AnimateToOpacity(visible_opacity_,
-                       GetAnimationDuration(ACTIVATED_FADE_IN),
-                       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                       gfx::Tween::EASE_IN, animation_observer);
-      AnimateToTransform(GetMaxSizeTargetTransform(),
-                         GetAnimationDuration(ACTIVATED_TRANSFORM),
+      if (old_ink_drop_state == InkDropState::ACTION_PENDING) {
+        // The final state of pending animation is the same as the final state
+        // of activated animation. We only need to enqueue a zero-length pause
+        // so that animation observers are notified in order.
+        PauseOpacityAnimation(
+            base::TimeDelta(),
+            ui::LayerAnimator::PreemptionStrategy::ENQUEUE_NEW_ANIMATION,
+            animation_observer);
+        PauseTransformAnimation(
+            base::TimeDelta(),
+            ui::LayerAnimator::PreemptionStrategy::ENQUEUE_NEW_ANIMATION,
+            animation_observer);
+      } else {
+        AnimateToOpacity(visible_opacity_,
+                         GetAnimationDuration(ACTIVATED_FADE_IN),
                          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
-                         gfx::Tween::EASE_IN_OUT, animation_observer);
+                         gfx::Tween::EASE_IN, animation_observer);
+        AnimateToTransform(GetMaxSizeTargetTransform(),
+                           GetAnimationDuration(ACTIVATED_TRANSFORM),
+                           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET,
+                           gfx::Tween::EASE_IN_OUT, animation_observer);
+      }
       break;
     }
     case InkDropState::DEACTIVATED:
@@ -313,6 +326,27 @@ void FloodFillInkDropRipple::AnimateToTransform(
   animator->StartAnimation(sequence);
 }
 
+void FloodFillInkDropRipple::PauseTransformAnimation(
+    base::TimeDelta duration,
+    ui::LayerAnimator::PreemptionStrategy preemption_strategy,
+    ui::LayerAnimationObserver* observer) {
+  ui::LayerAnimator* animator = painted_layer_.GetAnimator();
+  ui::ScopedLayerAnimationSettings animation(animator);
+  animation.SetPreemptionStrategy(preemption_strategy);
+
+  std::unique_ptr<ui::LayerAnimationElement> element =
+      ui::LayerAnimationElement::CreatePauseElement(
+          ui::LayerAnimationElement::TRANSFORM, duration);
+
+  ui::LayerAnimationSequence* sequence =
+      new ui::LayerAnimationSequence(std::move(element));
+
+  if (observer)
+    sequence->AddObserver(observer);
+
+  animator->StartAnimation(sequence);
+}
+
 void FloodFillInkDropRipple::SetOpacity(float opacity) {
   root_layer_.SetOpacity(opacity);
 }
@@ -338,6 +372,27 @@ void FloodFillInkDropRipple::AnimateToOpacity(
   animator->StartAnimation(animation_sequence);
 }
 
+void FloodFillInkDropRipple::PauseOpacityAnimation(
+    base::TimeDelta duration,
+    ui::LayerAnimator::PreemptionStrategy preemption_strategy,
+    ui::LayerAnimationObserver* observer) {
+  ui::LayerAnimator* animator = root_layer_.GetAnimator();
+  ui::ScopedLayerAnimationSettings animation(animator);
+  animation.SetPreemptionStrategy(preemption_strategy);
+
+  std::unique_ptr<ui::LayerAnimationElement> element =
+      ui::LayerAnimationElement::CreatePauseElement(
+          ui::LayerAnimationElement::OPACITY, duration);
+
+  ui::LayerAnimationSequence* sequence =
+      new ui::LayerAnimationSequence(std::move(element));
+
+  if (observer)
+    sequence->AddObserver(observer);
+
+  animator->StartAnimation(sequence);
+}
+
 gfx::Transform FloodFillInkDropRipple::CalculateTransform(
     float target_radius) const {
   const float target_scale = target_radius / circle_layer_delegate_.radius();