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 179f91b7555e18d5558dd4929dc708bc232e6e82..86e7cdc8fa5c12361ab0aa42e943c4326646104f 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 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* min_value, double* max_value) const {
+  *min_value = 0;
+  *max_value = 1;
+}
+
+double FramesTimingFunction::Evaluate(double fraction, double) const {
+  return frames_->GetPreciseValue(fraction);
+}
+
+std::unique_ptr<cc::TimingFunction> FramesTimingFunction::CloneToCC() const {
+  return frames_->Clone();
+}
+
 PassRefPtr<TimingFunction> CreateCompositorTimingFunctionFromCC(
     const cc::TimingFunction* timing_function) {
   if (!timing_function)
@@ -169,6 +190,14 @@ 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& ftf = ToFramesTimingFunction(rhs);
+  return lhs.NumberOfFrames() == ftf.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) {
@@ -185,6 +214,10 @@ 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();
   }