chromeos: Update note-taking apps when ARC-enabled profile added.

chrome/browser/chromeos/note_taking_helper.cc

Index: chrome/browser/chromeos/note_taking_helper.cc
diff --git a/chrome/browser/chromeos/note_taking_helper.cc b/chrome/browser/chromeos/note_taking_helper.cc
index 8465c18f9ec51e20c6b9f8375370a3948b743030..b4e003a1587722edc666b95312feaeedf15f9683 100644
--- a/chrome/browser/chromeos/note_taking_helper.cc
+++ b/chrome/browser/chromeos/note_taking_helper.cc
@@ -391,10 +391,18 @@ void NoteTakingHelper::Observe(int type,
                                const content::NotificationSource& source,
                                const content::NotificationDetails& details) {
   DCHECK_EQ(type, chrome::NOTIFICATION_PROFILE_ADDED);
-  auto* registry = extensions::ExtensionRegistry::Get(
-      content::Source<Profile>(source).ptr());
+  Profile* profile = content::Source<Profile>(source).ptr();
+  DCHECK(profile);
+
+  auto* registry = extensions::ExtensionRegistry::Get(profile);
   DCHECK(!extension_registry_observer_.IsObserving(registry));
   extension_registry_observer_.Add(registry);
+
+  if (!play_store_enabled_ && arc::IsArcPlayStoreEnabledForProfile(profile)) {

[Yusuke Sato, 2017/03/27 21:38:47]

+1 for adding a TODO here. TODO(hidehiko) should be fine.

I tested tot Chrome, and in my case,
NoteTakingHelper::OnArcPlayStoreEnabledChanged() *is* always called shortly
after signing in. If there's a case where the callback is never called, we
should fix it.

[Daniel Erat, 2017/03/27 22:04:16]

Done.

+    play_store_enabled_ = true;
+    for (auto& observer : observers_)
+      observer.OnAvailableNoteTakingAppsUpdated();

[Daniel Erat, 2017/03/27 19:25:23]

this notification is since we're now waiting for android apps. it's covered by
tests, but let me know if you think this also justifies a comment here.

+  }
 }
 
 void NoteTakingHelper::OnExtensionLoaded(