Web Animations API: Implement step-middle and steps(x, middle) timing functions.

Source/core/animation/ElementAnimationTest.cpp

Index: Source/core/animation/ElementAnimationTest.cpp
diff --git a/Source/core/animation/ElementAnimationTest.cpp b/Source/core/animation/ElementAnimationTest.cpp
index bede5224d693e9b1de19fe0e046230463919bc92..cd6a481cbbf19448a84f722d27c4fada23edb4e3 100644
--- a/Source/core/animation/ElementAnimationTest.cpp
+++ b/Source/core/animation/ElementAnimationTest.cpp
@@ -564,6 +564,10 @@ TEST_F(AnimationElementAnimationTest, TimingInputTimingFunction)
     EXPECT_EQ(*(StepsTimingFunction::preset(StepsTimingFunction::Start)), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;
 
+    applyTimingInputString(timing, isolate, "easing", "step-middle");
+    EXPECT_EQ(*(StepsTimingFunction::preset(StepsTimingFunction::Middle)), *timing.timingFunction.get());
+    timing.timingFunction = defaultTimingFunction;
+
     applyTimingInputString(timing, isolate, "easing", "step-end");
     EXPECT_EQ(*(StepsTimingFunction::preset(StepsTimingFunction::End)), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;
@@ -573,19 +577,18 @@ TEST_F(AnimationElementAnimationTest, TimingInputTimingFunction)
     timing.timingFunction = defaultTimingFunction;
 
     applyTimingInputString(timing, isolate, "easing", "steps(3, start)");
-    EXPECT_EQ(*(StepsTimingFunction::create(3, true).get()), *timing.timingFunction.get());
+    EXPECT_EQ(*(StepsTimingFunction::create(3, StepsTimingFunction::StepAtStart).get()), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;
 
-    applyTimingInputString(timing, isolate, "easing", "steps(5, end)");
-    EXPECT_EQ(*(StepsTimingFunction::create(5, false).get()), *timing.timingFunction.get());
+    applyTimingInputString(timing, isolate, "easing", "steps(5, middle)");
+    EXPECT_EQ(*(StepsTimingFunction::create(5, StepsTimingFunction::StepAtMiddle).get()), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;
 
-    applyTimingInputString(timing, isolate, "easing", "steps(5.6, end)");
-    EXPECT_EQ(*defaultTimingFunction.get(), *timing.timingFunction.get());
+    applyTimingInputString(timing, isolate, "easing", "steps(5, end)");
+    EXPECT_EQ(*(StepsTimingFunction::create(5, StepsTimingFunction::StepAtEnd).get()), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;
 
-    // FIXME: Step-middle not yet implemented. Change this test when it is working.
-    applyTimingInputString(timing, isolate, "easing", "steps(5, middle)");
+    applyTimingInputString(timing, isolate, "easing", "steps(5.6, end)");
     EXPECT_EQ(*defaultTimingFunction.get(), *timing.timingFunction.get());
     timing.timingFunction = defaultTimingFunction;