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

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index be168e68a7bbb4d6b062fa2c284353ea24f2a164..10aa9eaad489e2086395cebf514ae5c9ecb8df6c 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -69,8 +69,6 @@
 #include "core/rendering/RenderListItem.h"
 #include "core/rendering/RenderText.h"
 
-using namespace std;
-
 namespace WebCore {
 
 using namespace HTMLNames;
@@ -762,7 +760,7 @@ void CompositeEditCommand::deleteInsignificantText(PassRefPtrWillBeRawPtr<Text>
         bool indicesIntersect = start <= gapEnd && end >= gapStart;
         int gapLen = gapEnd - gapStart;
         if (indicesIntersect && gapLen > 0) {
-            gapStart = max(gapStart, start);
+            gapStart = std::max(gapStart, start);
             if (str.isNull())
                 str = textNode->data().substring(start, end - start);
             // remove text in the gap