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

Source/core/platform/ScrollableArea.h

Index: Source/core/platform/ScrollableArea.h
diff --git a/Source/core/platform/ScrollableArea.h b/Source/core/platform/ScrollableArea.h
index 46f1495c15d5fed0ad475514583849590d983be9..4590a98f5dd8250b29d1443ffb056e9eb119df4f 100644
--- a/Source/core/platform/ScrollableArea.h
+++ b/Source/core/platform/ScrollableArea.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 ScrollableArea_h
@@ -148,7 +148,7 @@ public:
     virtual void scrollbarStyleChanged(int /*newStyle*/, bool /*forceUpdate*/) { }
 
     virtual bool scrollbarsCanBeActive() const = 0;
-    
+
     // Note that this only returns scrollable areas that can actually be scrolled.
     virtual ScrollableArea* enclosingScrollableArea() const = 0;
 
@@ -203,7 +203,7 @@ protected:
 
 private:
     void scrollPositionChanged(const IntPoint&);
-    
+
     // NOTE: Only called from the ScrollAnimator.
     friend class ScrollAnimator;
     void setScrollOffsetFromAnimation(const IntPoint&);