Delete RenderWidgetHostViewChildFrame on Destroy().

content/browser/frame_host/render_widget_host_view_guest.cc

Index: content/browser/frame_host/render_widget_host_view_guest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index 93ea21f4b63ecb978654fe2d436e40d19dd67445..2197f73ad506ddacd642f091dc8e44e4ade2ba92 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -239,10 +239,11 @@ void RenderWidgetHostViewGuest::RenderProcessGone(
 }
 
 void RenderWidgetHostViewGuest::Destroy() {
-  RenderWidgetHostViewChildFrame::Destroy();
-
   if (platform_view_)  // The platform view might have been destroyed already.
     platform_view_->Destroy();
+
+  // RenderWidgetHostViewChildFrame::Destroy destroys this object.
+  RenderWidgetHostViewChildFrame::Destroy();
 }
 
 gfx::Size RenderWidgetHostViewGuest::GetPhysicalBackingSize() const {