Cleanly detach XHR and other pending loader clients from Inspector.

third_party/WebKit/Source/core/inspector/InspectorInstrumentation.idl

 /*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 195 matching lines @@
     [Network]
     void willStartFetch(ExecutionContext*, ThreadableLoaderClient*);
 
     [Network]
     void didFailFetch(ExecutionContext*, ThreadableLoaderClient*);
 
     [Network]
     void didFinishFetch([Keep] ExecutionContext*, ThreadableLoaderClient*, const AtomicString& method, const String& url);
 
     [Network]
+    void detachClientRequest(ExecutionContext*, ThreadableLoaderClient*);

[yhirano, 2017/01/25 11:06:26]

Please mention that this can be called from a pre-finalizer.

[sof, 2017/01/25 11:44:30]

Hmm. I don't see the value of adding that comment, especially not here. Calling
detach/clear/dispose methods from prefinalizers, is something we do throughout
the codebase. Revivification bugs due to prefinalizer actions over-extending the
lifetime of a near-dead object, I cannot recall having seen many issues on since
introducing Oilpan prefinalizers, will be caught out by ASan.

It would be unexpected that a detach method like this would do something like
this in any case; detach means letting go.

[yhirano, 2017/01/27 07:57:59]

LocalFrame::detach does a lot of things so I don't think it's super-clear. I'm
asking for the comment because inspector is an external module from XHR.

[sof, 2017/01/27 08:40:35]

ok.. clarified.

+
+    [Network]
     void scriptImported(ExecutionContext*, unsigned long identifier, const String& sourceString);
 
     [DOMDebugger]
     void scriptExecutionBlockedByCSP(ExecutionContext*, const String& directiveText);
 
     [Network]
     void didReceiveScriptResponse(ExecutionContext*, unsigned long identifier);
 
     [DOM, Page]
     void domContentLoadedEventFired([Keep] LocalFrame*);
@@ skipping 98 matching lines @@
 
     [Worker]
     bool shouldWaitForDebuggerOnWorkerStart(ExecutionContext* context);
 
     [Network]
     bool shouldForceCORSPreflight(Document*);
 
     [Network]
     bool shouldBlockRequest(LocalFrame*, const ResourceRequest&);
 }