WTF/std normalization: replace WTF::Vector::last with ::back

third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
index 681c4c45220eb93b260ffe2715f7806aabc3d490..762ab7bff80d818af0700a35f89fe35f65b5c10f 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
@@ -106,12 +106,12 @@ class CompositingRequirementsUpdater::OverlapMap {
   }
 
   bool overlapsLayers(const IntRect& bounds, bool isClipped) const {
-    bool clippedOverlap = m_overlapStack.last().clipped.overlapsLayers(bounds);
+    bool clippedOverlap = m_overlapStack.back().clipped.overlapsLayers(bounds);
     if (isClipped)
       return clippedOverlap;
     // Unclipped is allowed to overlap clipped, but not vice-versa.
     return clippedOverlap ||
-           m_overlapStack.last().unclipped.overlapsLayers(bounds);
+           m_overlapStack.back().unclipped.overlapsLayers(bounds);
   }
 
   void beginNewOverlapTestingContext() {
@@ -130,9 +130,9 @@ class CompositingRequirementsUpdater::OverlapMap {
     // FIXME: we may be able to avoid this deep copy by rearranging how
     //        overlapMap state is managed.
     m_overlapStack[m_overlapStack.size() - 2].clipped.unite(
-        m_overlapStack.last().clipped);
+        m_overlapStack.back().clipped);
     m_overlapStack[m_overlapStack.size() - 2].unclipped.unite(
-        m_overlapStack.last().unclipped);
+        m_overlapStack.back().unclipped);
     m_overlapStack.pop_back();
   }