Migrate WTF::Vector::append() to ::push_back() [part 3 of N]

third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp b/third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp
index 62e9facc491d3c460c07f4d8d150bff3108691dc..74c7e88e0b5ba5b4bc802f7f5b6171c38d177825 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSParserSelector.cpp
@@ -40,7 +40,7 @@ CSSParserSelector::~CSSParserSelector() {
   std::unique_ptr<CSSParserSelector> selector = std::move(m_tagHistory);
   while (true) {
     std::unique_ptr<CSSParserSelector> next = std::move(selector->m_tagHistory);
-    toDelete.append(std::move(selector));
+    toDelete.push_back(std::move(selector));
     if (!next)
       break;
     selector = std::move(next);