Store the callstack of the IPC sender of ViewMsg_New

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index aae437eccf675b949c1f14058e2f1c680f971eff..4300b01ed4bc9730f39e820b3c49e561329b0543 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -675,7 +675,23 @@ RenderFrameImpl::RenderFrameImpl(RenderViewImpl* render_view, int routing_id)
       weak_factory_(this) {
   std::pair<RoutingIDFrameMap::iterator, bool> result =
       g_routing_id_frame_map.Get().insert(std::make_pair(routing_id_, this));
-  CHECK(result.second) << "Inserting a duplicate item.";
+  if (!result.second) {
+    // TODO(lfg): Temporary. We're about to force a crash, so save the debug
+    // info on the stack so we can recover it from the crash dumps.
+    RenderFrameImpl* duplicate = result.first->second;
+    const std::vector<unsigned long>& debug_info = render_view->debug_info();
+    const std::vector<unsigned long>& duplicate_debug_info =
+        duplicate->render_view()->debug_info();
+    unsigned long duplicate_stack_debug_info[128];
+    unsigned long stack_debug_info[128];
+    const int size = debug_info.size() > 128 ? 128 : debug_info.size();
+    const int duplicate_size =
+        duplicate_debug_info.size() > 128 ? 128 : duplicate_debug_info.size();
+    memcpy(&stack_debug_info, &debug_info[0], size * sizeof(unsigned long));

[nasko, 2015/03/16 18:38:26]

memcpy from the memory of a stl container sounds scary to me. Why not just loop
and copy over the addresses, which will be simpler and since this will be
crashing, performance isn't really critical.

Also, why can't we just use debug::Alias() to force values to show up on the
stack? Have you tried that route?

+    memcpy(&duplicate_stack_debug_info, &duplicate_debug_info[0],
+           duplicate_size * sizeof(unsigned long));
+    CHECK(result.second) << "Inserting a duplicate item.";
+  }
 
   RenderThread::Get()->AddRoute(routing_id_, this);