Remove old diagnostic crash reports.

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 4fd32bcea7af8e9b0bf3fded1823f47358f69111..9c75b2e8b49ab1688359124374a8f0c9c99ebf3c 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -283,8 +283,10 @@ bool RenderViewHostImpl::CreateRenderView(
   // https://crbug.com/575245.
   // TODO(creis): Remove this once we've found the cause.
   if (main_frame_routing_id_ != MSG_ROUTING_NONE &&
-      proxy_route_id != MSG_ROUTING_NONE)
+      proxy_route_id != MSG_ROUTING_NONE) {
+    NOTREACHED() << "Don't set both main_frame_routing_id_ and proxy_route_id";
     base::debug::DumpWithoutCrashing();
+  }
 
   GetWidget()->set_renderer_initialized(true);