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

Source/core/page/DragSession.h

Index: Source/core/page/DragSession.h
diff --git a/Source/core/page/DragSession.h b/Source/core/page/DragSession.h
index 0d3a75b0df91d6ee5958e7a0da2db4a9df1abf89..8c2e5e35d77a8b5b106fcce53578775dc34d10a8 100644
--- a/Source/core/page/DragSession.h
+++ b/Source/core/page/DragSession.h
@@ -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.
  */
 
 #ifndef DragSession_h
@@ -29,7 +29,7 @@
 #include "core/page/DragActions.h"
 
 namespace WebCore {
-    
+
 struct DragSession {
     DragOperation operation;
     bool mouseIsOverFileInput;