Fix trailing whitespace in .cpp, .h, and .idl files

Source/core/dom/RegisteredEventListener.h

Index: Source/core/dom/RegisteredEventListener.h
diff --git a/Source/core/dom/RegisteredEventListener.h b/Source/core/dom/RegisteredEventListener.h
index 23a718a08f9ec1aaf72cc1de607a854fe64aec5e..7dde5576a5c5bfffa370690d7a3a67623e9325e1 100644
--- a/Source/core/dom/RegisteredEventListener.h
+++ b/Source/core/dom/RegisteredEventListener.h
@@ -40,7 +40,7 @@ namespace WebCore {
         RefPtr<EventListener> listener;
         bool useCapture;
     };
-    
+
     inline bool operator==(const RegisteredEventListener& a, const RegisteredEventListener& b)
     {
         return *a.listener == *b.listener && a.useCapture == b.useCapture;