Cleanly detach XHR and other pending loader clients from Inspector.

third_party/WebKit/Source/modules/eventsource/EventSource.h

Index: third_party/WebKit/Source/modules/eventsource/EventSource.h
diff --git a/third_party/WebKit/Source/modules/eventsource/EventSource.h b/third_party/WebKit/Source/modules/eventsource/EventSource.h
index 33b22ee819f79ed7dd00348545ad0cad685eb981..0e0693310ba77acf65e661e790adafe6bf2fc604 100644
--- a/third_party/WebKit/Source/modules/eventsource/EventSource.h
+++ b/third_party/WebKit/Source/modules/eventsource/EventSource.h
@@ -59,6 +59,7 @@ class MODULES_EXPORT EventSource final
       public EventSourceParser::Client {
   DEFINE_WRAPPERTYPEINFO();
   USING_GARBAGE_COLLECTED_MIXIN(EventSource);
+  USING_PRE_FINALIZER(EventSource, dispose);
 
  public:
   static EventSource* create(ExecutionContext*,
@@ -102,6 +103,8 @@ class MODULES_EXPORT EventSource final
  private:
   EventSource(ExecutionContext*, const KURL&, const EventSourceInit&);
 
+  void dispose();
+
   void didReceiveResponse(unsigned long,
                           const ResourceResponse&,
                           std::unique_ptr<WebDataConsumerHandle>) override;