Perform full gcs when context disposals happen too frequent.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index f702166cd4d281965f2caba33a616888eb7cb0fb..d3103fdafa42080f42ba0e121429724ebef9c0dc 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -4481,12 +4481,10 @@ class V8_EXPORT Isolate {
   void LowMemoryNotification();
 
   /**
-   * Optional notification that a context has been disposed. V8 uses
-   * these notifications to guide the GC heuristic. Returns the number
-   * of context disposals - including this one - since the last time
-   * V8 had a chance to clean up.
+   * Optional notification that a context has been disposed. This may trigger
+   * a full garbage collection if invoked too frequently.
    */
-  int ContextDisposedNotification();
+  void ContextDisposedNotification();
 
  private:
   template<class K, class V, class Traits> friend class PersistentValueMap;