Add NULL check before CanPauseForPendingResizeOrRepaints

BUG=361569
TBR=dgozman

Review URL: https://codereview.chromium.org/232283002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262916 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/render_widget_host_view_mac.mm

@@ -2215,6 +2215,7 @@ void RenderWidgetHostViewMac::PauseForPendingResizeOrRepaintsAndDraw() {
   // overlay and underlay resize at the same time, let them both to have
   // some time waiting. See crbug.com/352020.
   if (underlay_view_ &&
+      underlay_view_->render_widget_host_ &&
       !underlay_view_->render_widget_host_->
           CanPauseForPendingResizeOrRepaints())
     return;