Implement frames() timing function

third_party/WebKit/Source/platform/animation/TimingFunction.cpp

Index: third_party/WebKit/Source/platform/animation/TimingFunction.cpp
diff --git a/third_party/WebKit/Source/platform/animation/TimingFunction.cpp b/third_party/WebKit/Source/platform/animation/TimingFunction.cpp
index 5749dbc5ea1e48a37b98b90ad695237e2c678a7b..9a5a0d6a49266847a0c769d1356ad278a5646611 100644
--- a/third_party/WebKit/Source/platform/animation/TimingFunction.cpp
+++ b/third_party/WebKit/Source/platform/animation/TimingFunction.cpp
@@ -108,6 +108,27 @@ std::unique_ptr<cc::TimingFunction> StepsTimingFunction::cloneToCC() const {
   return m_steps->Clone();
 }
 
+String FramesTimingFunction::toString() const {
+  StringBuilder builder;
+  builder.append("frames(");
+  builder.append(String::numberToStringECMAScript(this->numberOfFrames()));
+  builder.append(")");
+  return builder.toString();
+}
+
+void FramesTimingFunction::range(double* minValue, double* maxValue) const {
+  *minValue = 0;
+  *maxValue = 1;
+}
+
+double FramesTimingFunction::evaluate(double fraction, double) const {
+  return m_frames->GetPreciseValue(fraction);
+}
+
+std::unique_ptr<cc::TimingFunction> FramesTimingFunction::cloneToCC() const {
+  return m_frames->Clone();
+}
+
 PassRefPtr<TimingFunction> createCompositorTimingFunctionFromCC(
     const cc::TimingFunction* timingFunction) {
   if (!timingFunction)
@@ -168,6 +189,14 @@ bool operator==(const StepsTimingFunction& lhs, const TimingFunction& rhs) {
          (lhs.getStepPosition() == stf.getStepPosition());
 }
 
+bool operator==(const FramesTimingFunction& lhs, const TimingFunction& rhs) {
+  if (rhs.getType() != TimingFunction::Type::FRAMES)
+    return false;
+
+  const FramesTimingFunction& stf = toFramesTimingFunction(rhs);
+  return lhs.numberOfFrames() == stf.numberOfFrames();
+}
+
 // The generic operator== *must* come after the
 // non-generic operator== otherwise it will end up calling itself.
 bool operator==(const TimingFunction& lhs, const TimingFunction& rhs) {
@@ -184,6 +213,10 @@ bool operator==(const TimingFunction& lhs, const TimingFunction& rhs) {
       const StepsTimingFunction& step = toStepsTimingFunction(lhs);
       return (step == rhs);
     }
+    case TimingFunction::Type::FRAMES: {
+      const FramesTimingFunction& frame = toFramesTimingFunction(lhs);
+      return (frame == rhs);
+    }
     default:
       ASSERT_NOT_REACHED();
   }