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

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index afd5e8b783fa0ece50a4750c5c9eee8c7ed932f7..60e54ba5908e2d3adfefb52caee62264cae1ee9f 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -2180,7 +2180,7 @@ void RenderWidget::didOverscroll(
   // fixed.
   params.current_fling_velocity =
       gfx::Vector2dF(-velocity.width, -velocity.height);
-  params.causal_event_viewport_point = gfx::PointF(position.x, position.y);
+  params.causal_event_viewport_point = gfx::Point(position.x, position.y);
 
   // If we're currently handling an event, stash the overscroll data such that
   // it can be bundled in the event ack.