Migrate WTF::LinkedHashSet/ListHashSet::removeLast() to ::pop_back()

As discussed on platform-architecture-dev [0], there is interest in
normalizing the methods of WTF classes to better align with std classes.

There are no functional changes.

[0] https://groups.google.com/a/chromium.org/d/topic/platform-architecture-dev/I7jnz4p1h84/discussion

BUG=662431

Review-Url: https://codereview.chromium.org/2743743002
Cr-Commit-Position: refs/heads/master@{#455792}

third_party/WebKit/Source/wtf/LinkedHashSet.h

@@ -241,7 +241,7 @@ class LinkedHashSet {
 
   Value& back();
   const Value& back() const;
-  void removeLast();
+  void pop_back();
 
   iterator find(ValuePeekInType);
   const_iterator find(ValuePeekInType) const;
@@ -730,7 +730,7 @@ inline const T& LinkedHashSet<T, U, V, W>::back() const {
 }
 
 template <typename T, typename U, typename V, typename W>
-inline void LinkedHashSet<T, U, V, W>::removeLast() {
+inline void LinkedHashSet<T, U, V, W>::pop_back() {
   DCHECK(!isEmpty());
   m_impl.remove(static_cast<Node*>(m_anchor.m_prev));
 }

third_party/WebKit/Source/wtf/ListHashSet.h

@@ -169,7 +169,7 @@ class ListHashSet
 
   ValueType& back();
   const ValueType& back() const;
-  void removeLast();
+  void pop_back();
 
   iterator find(ValuePeekInType);
   const_iterator find(ValuePeekInType) const;
@@ -840,7 +840,7 @@ inline const T& ListHashSet<T, inlineCapacity, U, V>::back() const {
 }
 
 template <typename T, size_t inlineCapacity, typename U, typename V>
-inline void ListHashSet<T, inlineCapacity, U, V>::removeLast() {
+inline void ListHashSet<T, inlineCapacity, U, V>::pop_back() {
   DCHECK(!isEmpty());
   m_impl.remove(m_tail);
   unlinkAndDelete(m_tail);

third_party/WebKit/Source/wtf/ListHashSetTest.cpp

@@ -60,7 +60,7 @@ TYPED_TEST(ListOrLinkedHashSetTest, RemoveFirst) {
   list.removeFirst();
   EXPECT_EQ(0, list.front());
 
-  list.removeLast();
+  list.pop_back();
   EXPECT_EQ(2, list.back());
 
   list.removeFirst();