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

Source/core/frame/DOMTimer.cpp

Index: Source/core/frame/DOMTimer.cpp
diff --git a/Source/core/frame/DOMTimer.cpp b/Source/core/frame/DOMTimer.cpp
index 4d9b76a27ffb9fba1618359ff4efdef59de5f0cd..9013180c62fb6e78c85a190029e94c93b7e96443 100644
--- a/Source/core/frame/DOMTimer.cpp
+++ b/Source/core/frame/DOMTimer.cpp
@@ -33,6 +33,8 @@
 #include "platform/TraceEvent.h"
 #include "wtf/CurrentTime.h"
 
+using namespace std;
+
 namespace WebCore {
 
 static const int maxIntervalForUserGestureForwarding = 1000; // One second matches Gecko.
@@ -96,7 +98,7 @@
     if (shouldForwardUserGesture(interval, m_nestingLevel))
         m_userGestureToken = UserGestureIndicator::currentToken();
 
-    double intervalMilliseconds = std::max(oneMillisecond, interval * oneMillisecond);
+    double intervalMilliseconds = max(oneMillisecond, interval * oneMillisecond);
     if (intervalMilliseconds < minimumInterval && m_nestingLevel >= maxTimerNestingLevel)
         intervalMilliseconds = minimumInterval;
     if (singleShot)