Throw TypeError if easing string is invalid.

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

Index: third_party/WebKit/Source/core/animation/AnimationInputHelpers.cpp
diff --git a/third_party/WebKit/Source/core/animation/AnimationInputHelpers.cpp b/third_party/WebKit/Source/core/animation/AnimationInputHelpers.cpp
index 68071a95fcb07f152b93530d5c72f216bfa428ed..460620613e2e613cf121e14c52926f90c5adf175 100644
--- a/third_party/WebKit/Source/core/animation/AnimationInputHelpers.cpp
+++ b/third_party/WebKit/Source/core/animation/AnimationInputHelpers.cpp
@@ -4,6 +4,7 @@
 
 #include "core/animation/AnimationInputHelpers.h"
 
+#include "bindings/core/v8/ExceptionState.h"
 #include "core/SVGNames.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParser.h"
@@ -201,19 +202,24 @@ const QualifiedName* AnimationInputHelpers::keyframeAttributeToSVGAttribute(cons
     return iter->value;
 }
 
-PassRefPtr<TimingFunction> AnimationInputHelpers::parseTimingFunction(const String& string)
+PassRefPtr<TimingFunction> AnimationInputHelpers::parseTimingFunction(const String& string, ExceptionState& exceptionState)
 {
-    if (string.isEmpty())
+    if (string.isEmpty()) {
+        exceptionState.throwTypeError("Easing may not be the empty string");
         return nullptr;
+    }
 
     CSSValue* value = CSSParser::parseSingleValue(CSSPropertyTransitionTimingFunction, string);
     if (!value || !value->isValueList()) {
         ASSERT(!value || value->isCSSWideKeyword());
+        exceptionState.throwTypeError("'" + string + "' is not a valid value for easing");
         return nullptr;
     }
     CSSValueList* valueList = toCSSValueList(value);
-    if (valueList->length() > 1)
+    if (valueList->length() > 1) {
+        exceptionState.throwTypeError("Easing may not be set to a list of values");
         return nullptr;
+    }
     return CSSToStyleMap::mapAnimationTimingFunction(*valueList->item(0), true);
 }