Fix serialization of step timing functions

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/animation/TimingFunction.h"
 
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
@@ skipping 68 matching lines @@
 {
     const char* positionString = nullptr;
     switch (getStepPosition()) {
     case StepPosition::START:
         positionString = "start";
         break;
     case StepPosition::MIDDLE:
         positionString = "middle";
         break;
     case StepPosition::END:
-        positionString = "end";
+        // do not specify step position in output
         break;
     }
 
     StringBuilder builder;
-    if (this->numberOfSteps() == 1) {
-        builder.append("step-");
-        builder.append(positionString);
-    } else {
-        builder.append("steps(");
-        builder.append(String::numberToStringECMAScript(this->numberOfSteps()));
+    builder.append("steps(");
+    builder.append(String::numberToStringECMAScript(this->numberOfSteps()));
+    if (positionString) {
         builder.append(", ");
         builder.append(positionString);
-        builder.append(')');
     }
+    builder.append(')');
     return builder.toString();
 }
 
 void StepsTimingFunction::range(double* minValue, double* maxValue) const
 {
     *minValue = 0;
     *maxValue = 1;
 }
 
 double StepsTimingFunction::evaluate(double fraction, double) const
@@ skipping 84 matching lines @@
     return false;
 }
 
 // No need to define specific operator!= as they can all come via this function.
 bool operator!=(const TimingFunction& lhs, const TimingFunction& rhs)
 {
     return !(lhs == rhs);
 }
 
 } // namespace blink