Temporarily CHECK that the swappedout:// URL isn't sent to the browser process.

content/browser/renderer_host/render_view_host_impl.cc

Index: content/browser/renderer_host/render_view_host_impl.cc
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 007de7fe5862f02dcc13dc4bf4eaf54b82d13fa0..4b01c50c233b71de16d3d238c1a39c5be07c42d8 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -1711,9 +1711,9 @@ void RenderViewHostImpl::FilterURL(ChildProcessSecurityPolicyImpl* policy,
     return;
 
   // The browser process should never hear the swappedout:// URL from any
-  // of the renderer's messages.  Check for this in debug builds, but don't
-  // let it crash a release browser.
-  DCHECK(GURL(kSwappedOutURL) != *url);
+  // of the renderer's messages.  Temporarily CHECK on a canary build to see if
+  // it's still happening in the wild.
+  CHECK(GURL(kSwappedOutURL) != *url);
 
   if (!url->is_valid()) {
     // Have to use about:blank for the denied case, instead of an empty GURL.