gfx: Make conversions from gfx::Point to PointF explicit.

ui/events/test/event_generator.h

Index: ui/events/test/event_generator.h
diff --git a/ui/events/test/event_generator.h b/ui/events/test/event_generator.h
index 6f84e80acb4529be5dcc9afe7e2ba576f5a5cdae..9a72695355a1bfcd7b1dbad06e5cb15baf601df1 100644
--- a/ui/events/test/event_generator.h
+++ b/ui/events/test/event_generator.h
@@ -21,6 +21,10 @@ namespace base {
 class TickClock;
 }
 
+namespace gfx {
+class PointF;
+}
+
 namespace ui {
 class Event;
 class EventProcessor;