Implement frames() timing function

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

Index: third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
diff --git a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
index 5394b40317a46dc87b92dbe6c144480c61213132..973ca2cbfdbcb063b8bbddb51c713325b0dfb4b9 100644
--- a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
+++ b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
@@ -1331,6 +1331,13 @@ static CSSValue* createTimingFunctionValue(
       return CSSIdentifierValue::create(valueId);
     }
 
+    case TimingFunction::Type::FRAMES: {
+      const FramesTimingFunction* framesTimingFunction =
+          toFramesTimingFunction(timingFunction);
+      int frames = framesTimingFunction->numberOfFrames();
+      return CSSFramesTimingFunctionValue::create(frames);
+    }
+
     default:
       return CSSIdentifierValue::create(CSSValueLinear);
   }