Throw TypeError if easing string is invalid.

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

Index: third_party/WebKit/Source/core/animation/KeyframeEffect.cpp
diff --git a/third_party/WebKit/Source/core/animation/KeyframeEffect.cpp b/third_party/WebKit/Source/core/animation/KeyframeEffect.cpp
index c727df720e6836267ced8c74546890918284b8ab..b9b2566d6be448651e12d2cf3cb2e11d2a9c3a42 100644
--- a/third_party/WebKit/Source/core/animation/KeyframeEffect.cpp
+++ b/third_party/WebKit/Source/core/animation/KeyframeEffect.cpp
@@ -58,15 +58,24 @@ KeyframeEffect* KeyframeEffect::create(ExecutionContext* executionContext, Eleme
     ASSERT(RuntimeEnabledFeatures::webAnimationsAPIEnabled());
     if (element)
         UseCounter::count(element->document(), UseCounter::AnimationConstructorKeyframeListEffectObjectTiming);
-    return create(element, EffectInput::convert(element, effectInput, executionContext, exceptionState), TimingInput::convert(duration));
+    Timing timing;
+    ASSERT(TimingInput::convert(duration, timing));

[alancutter (OOO until 2018), 2016/04/05 04:50:06]

ASSERTs don't get compiled into official builds, you must store the return value
separately if you want to assert on it.

[suzyh_UTC10 (ex-contributor), 2016/04/12 08:04:23]

Fixed.

+    return create(element, EffectInput::convert(element, effectInput, executionContext, exceptionState), timing);
 }
+
 KeyframeEffect* KeyframeEffect::create(ExecutionContext* executionContext, Element* element, const EffectModelOrDictionarySequenceOrDictionary& effectInput, const KeyframeEffectOptions& timingInput, ExceptionState& exceptionState)
 {
     ASSERT(RuntimeEnabledFeatures::webAnimationsAPIEnabled());
     if (element)
         UseCounter::count(element->document(), UseCounter::AnimationConstructorKeyframeListEffectObjectTiming);
-    return create(element, EffectInput::convert(element, effectInput, executionContext, exceptionState), TimingInput::convert(timingInput));
+    Timing timing;
+    bool success = TimingInput::convert(timingInput, timing, exceptionState);
+    if (!success || exceptionState.hadException())
+        return nullptr;
+
+    return create(element, EffectInput::convert(element, effectInput, executionContext, exceptionState), timing);
 }
+
 KeyframeEffect* KeyframeEffect::create(ExecutionContext* executionContext, Element* element, const EffectModelOrDictionarySequenceOrDictionary& effectInput, ExceptionState& exceptionState)
 {
     ASSERT(RuntimeEnabledFeatures::webAnimationsAPIEnabled());