Removing using declarations that import names in the C++ Standard library.

Source/core/rendering/RenderRubyText.cpp

Index: Source/core/rendering/RenderRubyText.cpp
diff --git a/Source/core/rendering/RenderRubyText.cpp b/Source/core/rendering/RenderRubyText.cpp
index 5e4697873474f4c48032fbd818bf29cdb61cf4e0..03683bd6a4f364f01217811c3b6d09daf9e78789 100644
--- a/Source/core/rendering/RenderRubyText.cpp
+++ b/Source/core/rendering/RenderRubyText.cpp
@@ -33,8 +33,6 @@
 
 #include "core/rendering/RenderRubyText.h"
 
-using namespace std;
-
 namespace WebCore {
 
 RenderRubyText::RenderRubyText(Element* element)
@@ -77,7 +75,7 @@ void RenderRubyText::adjustInlineDirectionLineBounds(unsigned expansionOpportuni
     // ruby character on each side.
     float inset = (logicalWidth - maxPreferredLogicalWidth) / (expansionOpportunityCount + 1);
     if (expansionOpportunityCount)
-        inset = min<float>(2 * style()->fontSize(), inset);
+        inset = std::min<float>(2 * style()->fontSize(), inset);
 
     logicalLeft += inset / 2;
     logicalWidth -= inset;