Migrate WTF::Vector::append() to ::push_back() [part 9 of N]

third_party/WebKit/Source/core/layout/LayoutMultiColumnSet.cpp

 /*
  * Copyright (C) 2012 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 594 matching lines @@
         ruleTop = paintOffset.y() + borderTop() + paddingTop();
         ruleBottom = ruleTop + contentHeight();
       } else {
         ruleLeft = paintOffset.x() + borderLeft() + paddingLeft();
         ruleRight = ruleLeft + contentWidth();
         ruleTop =
             paintOffset.y() + ruleLogicalLeft - ruleThickness / 2 + ruleAdd;
         ruleBottom = ruleTop + ruleThickness;
       }
 
-      columnRuleBounds.append(LayoutRect(
+      columnRuleBounds.push_back(LayoutRect(
           ruleLeft, ruleTop, ruleRight - ruleLeft, ruleBottom - ruleTop));
     }
 
     ruleLogicalLeft = currLogicalLeftOffset;
   }
   return true;
 }
 
 LayoutRect LayoutMultiColumnSet::localVisualRect() const {
   LayoutRect blockFlowBounds = LayoutBlockFlow::localVisualRect();
 
   // Now add in column rule bounds, if present.
   Vector<LayoutRect> columnRuleBounds;
   if (computeColumnRuleBounds(LayoutPoint(), columnRuleBounds)) {
     for (auto& bound : columnRuleBounds)
       blockFlowBounds.unite(bound);
   }
   return blockFlowBounds;
 }
 
 }  // namespace blink