Shut down Profile's URLRequestContextGetters safely.

chrome/browser/net/chrome_url_request_context_getter.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_NET_CHROME_URL_REQUEST_CONTEXT_GETTER_H_
 #define CHROME_BROWSER_NET_CHROME_URL_REQUEST_CONTEXT_GETTER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 61 matching lines @@
       content::URLRequestInterceptorScopedVector request_interceptors);
 
   // Create an instance for an original profile for media with isolated
   // storage. This is expected to get called on UI thread.
   static ChromeURLRequestContextGetter* CreateForIsolatedMedia(
       Profile* profile,
       ChromeURLRequestContextGetter* app_context,
       const ProfileIOData* profile_io_data,
       const StoragePartitionDescriptor& partition_descriptor);
 
-  // Discard reference to URLRequestContext.
-  // Access only from the IO thread.
-  void Invalidate();
+  // Discard reference to URLRequestContext and inform observers of shutdown.
+  // Must be called before destruction. May only be called on IO thread.
+  void NotifyContextShuttingDown();

[davidben, 2015/05/14 17:09:26]

Maybe keep this called Invalidate or rename it to something else? I think having
a non-virtual override is probably better avoided. (They also do subtly
different things anyway. The base class's one is "By the way, I just made the
context start returning null. Please tell the observers". The subclass is "By
the way, that factory I constructed you with needs to be destroyed because it
references a dying ProfileIOData. Please deal."

[mmenke, 2015/05/14 19:23:52]

Done - was on the fence about naming, happy to defer to your opinion.  Switched
back to Invalidate.

 
  private:
   ~ChromeURLRequestContextGetter() override;
 
   // Deferred logic for creating a URLRequestContext.
   // Access only from the IO thread.
   scoped_ptr<ChromeURLRequestContextFactory> factory_;
 
   // NULL before initialization and after invalidation.
   // Otherwise, it is the URLRequestContext instance that
   // was lazily created by GetURLRequestContext().
   // Access only from the IO thread.
   net::URLRequestContext* url_request_context_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeURLRequestContextGetter);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_URL_REQUEST_CONTEXT_GETTER_H_