Test theory about didCommitProvisionalLoad crash.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index ec0938163cdf6c70261ee7f38f8807025c098a19..e1ce6bb2e4c5ebd765ddaf025ae84a5504cbfaf3 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -691,13 +691,13 @@ void RenderViewImpl::Initialize(const ViewMsg_New_Params& params,
   if (params.proxy_routing_id != MSG_ROUTING_NONE) {
     CHECK(params.swapped_out);
     if (main_render_frame_) {
-      DCHECK(!SiteIsolationPolicy::IsSwappedOutStateForbidden());
+      CHECK(!SiteIsolationPolicy::IsSwappedOutStateForbidden());

[Charlie Reis, 2016/01/22 18:00:51]

I suspect that we'll fail this check rather than crash in
didCommitProvisionalLoad, based on the params I saw in crash reports.  It looks
like the RenderView has *both* a main frame routing ID and a proxy ID, which (I
think) shouldn't be possible anymore.

       RenderFrameProxy* proxy = RenderFrameProxy::CreateProxyToReplaceFrame(
           main_render_frame_, params.proxy_routing_id,
           blink::WebTreeScopeType::Document);
       main_render_frame_->set_render_frame_proxy(proxy);
     } else {
-      DCHECK(SiteIsolationPolicy::IsSwappedOutStateForbidden());
+      CHECK(SiteIsolationPolicy::IsSwappedOutStateForbidden());
       // Pass MSG_ROUTING_NONE for opener, since actual opener (if any) will be
       // set separately below.
       RenderFrameProxy::CreateFrameProxy(params.proxy_routing_id, routing_id(),