Add debuggin CHECK to help track down ExtensionHost crasher

chrome/browser/extensions/extension_host.cc

Index: chrome/browser/extensions/extension_host.cc
diff --git a/chrome/browser/extensions/extension_host.cc b/chrome/browser/extensions/extension_host.cc
index 321a0f035ac7534d6cb3076d29ef53ed3f8ab72c..a9835758a5f64a13f8e6699c6412110a354ce120 100644
--- a/chrome/browser/extensions/extension_host.cc
+++ b/chrome/browser/extensions/extension_host.cc
@@ -156,6 +156,14 @@ ExtensionHost::~ExtensionHost() {
       Details<ExtensionHost>(this));
   ProcessCreationQueue::get()->Remove(this);
   render_view_host_->Shutdown();  // deletes render_view_host
+
+  if (recently_deleted()->size() >= 20)
+    recently_deleted()->pop_front();
+  recently_deleted()->push_back(this);
+}
+
+ExtensionHost::HostPointerList* ExtensionHost::recently_deleted() {
+  return Singleton<HostPointerList>::get();
 }
 
 void ExtensionHost::CreateView(Browser* browser) {