Migrate WTF::Vector::append() to ::push_back() [part 2 of N]

third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp

Index: third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp
diff --git a/third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp b/third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp
index 5b2e06bf139da176d862da419baa9830a4530827..eceb57140fdeca09b94f62b909904af87e3424bd 100644
--- a/third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp
+++ b/third_party/WebKit/Source/core/animation/css/CSSTimingData.cpp
@@ -9,9 +9,9 @@
 namespace blink {
 
 CSSTimingData::CSSTimingData() {
-  m_delayList.append(initialDelay());
-  m_durationList.append(initialDuration());
-  m_timingFunctionList.append(initialTimingFunction());
+  m_delayList.push_back(initialDelay());
+  m_durationList.push_back(initialDuration());
+  m_timingFunctionList.push_back(initialTimingFunction());
 }
 
 CSSTimingData::CSSTimingData(const CSSTimingData& other)