ozone: evdev: Don't crash without cursor in scroll & click events

TEST=chrome --ozone-platform=gbm
BUG=none
NOTRY=true

Review URL: https://codereview.chromium.org/302093004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274281 0039d316-1c4b-4281-b951-d872f2087c98

ui/events/ozone/evdev/libgestures_glue/gesture_interpreter_libevdev_cros.cc

@@ -209,6 +209,8 @@ void GestureInterpreterLibevdevCros::OnGestureMove(const Gesture* gesture,
 void GestureInterpreterLibevdevCros::OnGestureScroll(
     const Gesture* gesture,
     const GestureScroll* scroll) {
+  if (!cursor_)
+    return;  // No cursor!
   DVLOG(3) << base::StringPrintf("Gesture Scroll: (%f, %f) [%f, %f]",
                                  scroll->dx,
                                  scroll->dy,
@@ -255,6 +257,8 @@ void GestureInterpreterLibevdevCros::Dispatch(Event* event) {
 
 void GestureInterpreterLibevdevCros::DispatchMouseButton(unsigned int modifier,
                                                          bool down) {
+  if (!cursor_)
+    return;  // No cursor!
   const gfx::PointF& loc = cursor_->location();
   int flag = modifiers_->GetEventFlagFromModifier(modifier);
   EventType type = (down ? ET_MOUSE_PRESSED : ET_MOUSE_RELEASED);