Remove DCHECK in DialRegistry dtor. This may trigger on browser shutdown if

chrome/browser/extensions/api/dial/dial_api.h

 // Copyright (c) 2012 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_EXTENSIONS_API_DIAL_DIAL_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/extensions/api/dial/dial_device_data.h"
 #include "chrome/browser/extensions/api/dial/dial_registry.h"
 #include "components/keyed_service/core/refcounted_keyed_service.h"
 #include "extensions/browser/api/async_api_function.h"
 #include "extensions/browser/event_router.h"
 
 namespace extensions {
 
 class DialRegistry;
 
 // Dial API which is a ref-counted KeyedService that manages
 // the DIAL registry. It takes care of creating the registry on the IO thread
 // and is an observer of the registry. It makes sure devices events are sent out
 // to extension listeners on the right thread.
+//
+// TODO(mfoltz): This should probably inherit from BrowserContextKeyedAPI
+// instead, as there is nothing refcounted on the UI thread we are explicitly
+// managing here; ShutdownOnUIThread below is a no-op.

[Wez, 2015/02/19 22:48:32]

This comment's pretty confusing; are you saying that there are no resources that
this class manages that require UI thread teardown? Or something else?

 class DialAPI : public RefcountedKeyedService,
                 public EventRouter::Observer,
                 public DialRegistry::Observer {
  public:
   explicit DialAPI(Profile* profile);
 
   // The DialRegistry for the API. This must always be used only from the IO
   // thread.
   DialRegistry* dial_registry();
 
@@ skipping 59 matching lines @@
   bool result_;
 
   DISALLOW_COPY_AND_ASSIGN(DialDiscoverNowFunction);
 };
 
 }  // namespace api
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_API_H_