Implement Gesture event hit testing/forwarding for OOPIF.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index e1a196bd9a530b5776b7c639462f2f1f2900c35f..62b0b38f1815d6ba4c322c55d0ec2a3684f92878 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -1615,6 +1615,12 @@ void RenderWidgetHostViewMac::ProcessTouchEvent(
   render_widget_host_->ForwardTouchEventWithLatencyInfo(event, latency);
 }
 
+void RenderWidgetHostViewMac::ProcessGestureEvent(
+    const blink::WebGestureEvent& event,
+    const ui::LatencyInfo& latency) {
+  render_widget_host_->ForwardGestureEventWithLatencyInfo(event, latency);
+}
+
 void RenderWidgetHostViewMac::TransformPointToLocalCoordSpace(
     const gfx::Point& point,
     cc::SurfaceId original_surface,