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

Source/core/page/ContextMenuController.cpp

Index: Source/core/page/ContextMenuController.cpp
diff --git a/Source/core/page/ContextMenuController.cpp b/Source/core/page/ContextMenuController.cpp
index 49e2a58fa9512d4e2920f4204d667dd83e2bdbb5..c12a904cd04c6094e9f18738056d3aaca3df4adf 100644
--- a/Source/core/page/ContextMenuController.cpp
+++ b/Source/core/page/ContextMenuController.cpp
@@ -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.
  */
 
 #include "config.h"
@@ -92,7 +92,7 @@ void ContextMenuController::showContextMenu(Event* event, PassRefPtr<ContextMenu
 PassOwnPtr<ContextMenu> ContextMenuController::createContextMenu(Event* event)
 {
     ASSERT(event);
-    
+
     if (!event->isMouseEvent())
         return nullptr;