Use abs() instead of std::abs() in Editor::firstRectForRange().

Source/core/editing/Editor.cpp

Index: Source/core/editing/Editor.cpp
===================================================================
--- Source/core/editing/Editor.cpp	(revision 176039)
+++ Source/core/editing/Editor.cpp	(working copy)
@@ -1132,7 +1132,7 @@
         // start and end are on the same line
         return IntRect(std::min(startCaretRect.x(), endCaretRect.x()),
             startCaretRect.y(),
-            std::abs(endCaretRect.x() - startCaretRect.x()),
+            ::abs(endCaretRect.x() - startCaretRect.x()),
             std::max(startCaretRect.height(), endCaretRect.height()));
     }