Deal with frame removal by content scripts

content/public/renderer/content_renderer_client.h

Index: content/public/renderer/content_renderer_client.h
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 241d95b535d65e592f5c9c4bb5faa36588d9b09c..6e0c710397a07fbaafce2aa0e38b7f2722cfac7d 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -14,7 +14,6 @@
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "content/public/common/content_client.h"
 #include "third_party/WebKit/public/platform/WebPageVisibilityState.h"
@@ -305,6 +304,15 @@ class CONTENT_EXPORT ContentRendererClient {
       const blink::WebURLResponse& response,
       std::map<std::string, std::string>* properties) {}
 
+  // Notifies that a document element has been inserted in the frame's document.
+  // This may be called multiple times for the same document. This method may
+  // invalidate the frame.

[esprehn, 2016/02/17 01:43:47]

This should be specific to extensions, This should be
NotifyExtensionsAfterDidCreateDocumentElement.

+  virtual void AfterDidCreateDocumentElement(RenderFrame* render_frame) {}
+
+  // Notifies that the DOM is ready in the frame's document.
+  // This method may invalidate the frame.
+  virtual void AfterDidFinishDocumentLoad(RenderFrame* render_frame) {}

[esprehn, 2016/02/17 01:43:47]

ditto

+
   // Notifies that a service worker context has been created. This function
   // is called from the worker thread.
   virtual void DidInitializeServiceWorkerContextOnWorkerThread(