Fix Win64 compile error caused by r12272.

src/extensions/statistics-extension.cc

Index: src/extensions/statistics-extension.cc
diff --git a/src/extensions/statistics-extension.cc b/src/extensions/statistics-extension.cc
index c5977208524b0f506677966d1a07b14feb42d71b..7ae090c987bef6b6bac1eb7b829aedcdc4266220 100644
--- a/src/extensions/statistics-extension.cc
+++ b/src/extensions/statistics-extension.cc
@@ -51,9 +51,10 @@ static void AddCounter(v8::Local<v8::Object> object,
 }
 
 static void AddNumber(v8::Local<v8::Object> object,
-                      double value,
+                      intptr_t value,
                       const char* name) {
-  object->Set(v8::String::New(name), v8::Number::New(value));
+  object->Set(v8::String::New(name),
+              v8::Number::New(static_cast<double>(value)));
 }