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

Source/core/dom/MessageEvent.idl

Index: Source/core/dom/MessageEvent.idl
diff --git a/Source/core/dom/MessageEvent.idl b/Source/core/dom/MessageEvent.idl
index 7b5fec34f0fd91bd1f9073256f872cf9d8e9a6dd..3bc8866a7ea1161a7c75dadb015e8e6873ad2cd7 100644
--- a/Source/core/dom/MessageEvent.idl
+++ b/Source/core/dom/MessageEvent.idl
@@ -21,7 +21,7 @@
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 
@@ -35,13 +35,13 @@
     [InitializedByEventConstructor, CustomGetter] readonly attribute any data;
     [InitializedByEventConstructor] readonly attribute MessagePort[] ports;
 
-    [Custom] void initMessageEvent([Default=Undefined] optional DOMString typeArg, 
-                                   [Default=Undefined] optional boolean canBubbleArg, 
-                                   [Default=Undefined] optional boolean cancelableArg, 
-                                   [Default=Undefined] optional any dataArg, 
-                                   [Default=Undefined] optional DOMString originArg, 
-                                   [Default=Undefined] optional DOMString lastEventIdArg, 
-                                   [Default=Undefined] optional Window sourceArg, 
+    [Custom] void initMessageEvent([Default=Undefined] optional DOMString typeArg,
+                                   [Default=Undefined] optional boolean canBubbleArg,
+                                   [Default=Undefined] optional boolean cancelableArg,
+                                   [Default=Undefined] optional any dataArg,
+                                   [Default=Undefined] optional DOMString originArg,
+                                   [Default=Undefined] optional DOMString lastEventIdArg,
+                                   [Default=Undefined] optional Window sourceArg,
                                    [Default=Undefined] optional Array messagePorts);
 
     [Custom] void webkitInitMessageEvent([Default=Undefined] optional DOMString typeArg,