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

Source/core/dom/OverflowEvent.idl

Index: Source/core/dom/OverflowEvent.idl
diff --git a/Source/core/dom/OverflowEvent.idl b/Source/core/dom/OverflowEvent.idl
index 04a86c82546b5f4e0b1c2159a3bab0721fb8ac43..69adee9a5780c376bab2302faa0b530d97e14ac2 100644
--- a/Source/core/dom/OverflowEvent.idl
+++ b/Source/core/dom/OverflowEvent.idl
@@ -20,7 +20,7 @@
  * 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.
  */
 
 [
@@ -29,7 +29,7 @@
     const unsigned short HORIZONTAL = 0;
     const unsigned short VERTICAL   = 1;
     const unsigned short BOTH       = 2;
-    
+
     [InitializedByEventConstructor] readonly attribute unsigned short orient;
     [InitializedByEventConstructor] readonly attribute boolean horizontalOverflow;
     [InitializedByEventConstructor] readonly attribute boolean verticalOverflow;