Discard SampledEffects on elements if they are redundant

third_party/WebKit/Source/core/animation/AnimationStackTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/animation/AnimationStack.h"
 
 #include "core/animation/AnimationClock.h"
 #include "core/animation/AnimationTimeline.h"
 #include "core/animation/ElementAnimations.h"
 #include "core/animation/KeyframeEffectModel.h"
@@ skipping 22 matching lines @@
         animation->update(TimingUpdateOnDemand);
         return animation;
     }
 
     void updateTimeline(double time)
     {
         document->animationClock().updateTime(document->timeline().zeroTime() + time);
         timeline->serviceAnimations(TimingUpdateForAnimationFrame);
     }
 
+    size_t sampledEffectCount()
+    {
+        return element->ensureElementAnimations().animationStack().m_sampledEffects.size();
+    }
+
     EffectModel* makeEffectModel(CSSPropertyID id, PassRefPtr<AnimatableValue> value)
     {
         AnimatableValueKeyframeVector keyframes(2);
         keyframes[0] = AnimatableValueKeyframe::create();
         keyframes[0]->setOffset(0.0);
         keyframes[0]->setPropertyValue(id, value.get());
         keyframes[1] = AnimatableValueKeyframe::create();
         keyframes[1]->setOffset(1.0);
         keyframes[1]->setPropertyValue(id, value.get());
         return AnimatableValueKeyframeEffectModel::create(keyframes);
@@ skipping 67 matching lines @@
     Animation* animation = play(makeKeyframeEffect(makeEffectModel(CSSPropertyFontSize, AnimatableDouble::create(1))), 10);
     ActiveInterpolationsMap result = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), 0, 0, KeyframeEffect::DefaultPriority);
     EXPECT_EQ(1u, result.size());
     EXPECT_TRUE(interpolationValue(result, CSSPropertyFontSize)->equals(AnimatableDouble::create(1).get()));
 
     animation->setEffect(0);
     result = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), 0, 0, KeyframeEffect::DefaultPriority);
     EXPECT_EQ(0u, result.size());
 }
 
+TEST_F(AnimationAnimationStackTest, ForwardsFillDiscarding)
+{
+    play(makeKeyframeEffect(makeEffectModel(CSSPropertyFontSize, AnimatableDouble::create(1))), 2);
+    play(makeKeyframeEffect(makeEffectModel(CSSPropertyFontSize, AnimatableDouble::create(2))), 6);
+    play(makeKeyframeEffect(makeEffectModel(CSSPropertyFontSize, AnimatableDouble::create(3))), 4);
+    document->compositorPendingAnimations().update();
+    ActiveInterpolationsMap interpolations;
+
+    updateTimeline(11);
+    Heap::collectAllGarbage();
+    interpolations = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), nullptr, nullptr, KeyframeEffect::DefaultPriority);
+    EXPECT_EQ(1u, interpolations.size());
+    EXPECT_TRUE(interpolationValue(interpolations, CSSPropertyFontSize)->equals(AnimatableDouble::create(3).get()));
+    EXPECT_EQ(3u, sampledEffectCount());
+
+    updateTimeline(13);
+    Heap::collectAllGarbage();
+    interpolations = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), nullptr, nullptr, KeyframeEffect::DefaultPriority);
+    EXPECT_EQ(1u, interpolations.size());
+    EXPECT_TRUE(interpolationValue(interpolations, CSSPropertyFontSize)->equals(AnimatableDouble::create(3).get()));
+    EXPECT_EQ(3u, sampledEffectCount());
+
+    updateTimeline(15);
+    Heap::collectAllGarbage();
+    interpolations = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), nullptr, nullptr, KeyframeEffect::DefaultPriority);
+    EXPECT_EQ(1u, interpolations.size());
+    EXPECT_TRUE(interpolationValue(interpolations, CSSPropertyFontSize)->equals(AnimatableDouble::create(3).get()));
+    EXPECT_EQ(2u, sampledEffectCount());
+
+    updateTimeline(17);
+    Heap::collectAllGarbage();
+    interpolations = AnimationStack::activeInterpolations(&element->elementAnimations()->animationStack(), nullptr, nullptr, KeyframeEffect::DefaultPriority);
+    EXPECT_EQ(1u, interpolations.size());
+    EXPECT_TRUE(interpolationValue(interpolations, CSSPropertyFontSize)->equals(AnimatableDouble::create(3).get()));
+    EXPECT_EQ(1u, sampledEffectCount());
+}
+
 } // namespace blink