Move ownership of AppSorting from ExtensionPrefs to ExtensionSystem

extensions/browser/app_window/app_window_geometry_cache_unittest.cc

Index: extensions/browser/app_window/app_window_geometry_cache_unittest.cc
diff --git a/extensions/browser/app_window/app_window_geometry_cache_unittest.cc b/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
index e1f4068440298217262576b2c982b80a4972d15f..1600693ae181cfb45aa3f51360583df1cb3da0d7 100644
--- a/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
+++ b/extensions/browser/app_window/app_window_geometry_cache_unittest.cc
@@ -95,9 +95,10 @@ void AppWindowGeometryCacheTest::SetUp() {
       pref_service_.get(),
       browser_context()->GetPath().AppendASCII("Extensions"),
       extension_pref_value_map_.get(),
-      scoped_ptr<AppSorting>(new NullAppSorting),
       false /* extensions_disabled */,
       std::vector<ExtensionPrefsObserver*>()));
+  scoped_ptr<AppSorting> app_sorting(new NullAppSorting);
+  extension_prefs_->set_app_sorting(app_sorting.get());

[not at google - send to devlin, 2015/07/29 18:22:03]

... would making TestExtensionSystem use a NullAppSorting solve all of these,
and let you remove set_app_sorting?

[Marc Treib, 2015/07/30 14:04:12]

..and instead have ExtensionPrefs use
|ExtensionSystem::Get(context)->app_sorting()| instead to get the AppSorting?
Probably possible, yes, but not trivial - right now ExtensionPrefs doesn't have
a BrowserContext, and giving it one is non-trivial, since not all unit tests
even set up a profile.

[not at google - send to devlin, 2015/07/30 18:21:00]

Ah yeah. I saw ExtensionPrefs::Get(BrowserContext*) and figured there was
already a dependency. That is the function that everybody does call, so plugging
it through to actually a member variable of ExtensionPrefs is conceptually
straightforward?

Side note, why does ExtensionPrefs extend KeyedService?
BrowserContextKeyedService I could understand, but what is the point in
extending just KeyedService.

[Marc Treib, 2015/07/31 08:17:49]

Yes, the problem is just with tests that use an ExtensionPrefs, but not a
profile. Those will need special massaging to make this work.
BrowserContextKeyedService doesn't exist (anymore), I guess it's just been
renamed to KeyedService since it doesn't really relate to a BrowserContext?
BrowserContextKeyedService*Factory* exists though, and returns a KeyedService,
see
https://code.google.com/p/chromium/codesearch#chromium/src/components/keyed_s...

 
   cache_.reset(
       new AppWindowGeometryCache(browser_context(), extension_prefs_.get()));