Attempting to fix problems in 11571014.

chrome/renderer/extensions/native_handler.h

Index: chrome/renderer/extensions/native_handler.h
diff --git a/chrome/renderer/extensions/native_handler.h b/chrome/renderer/extensions/native_handler.h
index 36ef991806958932b5ff0d8952a73a08f016db46..82c86318ef89736de977d3565f53f352a5f6eb0f 100644
--- a/chrome/renderer/extensions/native_handler.h
+++ b/chrome/renderer/extensions/native_handler.h
@@ -16,10 +16,26 @@ namespace extensions {
 // TODO(koz): Rename this to NativeJavaScriptModule.
 class NativeHandler {
  public:
-  virtual ~NativeHandler() {}
+  NativeHandler();
+  virtual ~NativeHandler();
 
   // Create a new instance of the object this handler specifies.
   virtual v8::Handle<v8::Object> NewInstance() = 0;
+
+  // Invalidate this object so it cannot be used any more. This is needed
+  // because it's possible for this to outlive its owner context. Invalidate
+  // must be called before this happens.
+  //
+  // Subclasses should override to invalidate their own V8 state. If they do
+  // they must call their superclass' Invalidate().
+  virtual void Invalidate();
+
+ protected:
+  // Allow subclasses to query valid state.
+  bool is_valid() { return is_valid_; }
+
+ private:
+  bool is_valid_;
 };
 
 }  // extensions