Makes the extension resize gripper only visible when the mouse is over
it.

BUG=45750
TEST=see bug

Review URL: http://codereview.chromium.org/2800022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50515 0039d316-1c4b-4281-b951-d872f2087c98
void ResizeGripper::OnMouseReleased(const views::MouseEvent& event,
                                    bool canceled) {
  if (canceled)
     ReportResizeAmount(initial_position_, true);
   else
     ReportResizeAmount(event.x(), true);
  SetGripperVisible(HitTest(event.location()));
 }

void ResizeGripper::OnMouseReleased(const views::MouseEvent& event,
                                    bool canceled) {
  if (canceled)
     ReportResizeAmount(initial_position_, true);
   else
     ReportResizeAmount(event.x(), true);
 }
