TabManager: Set OOM scores via a new debugd interface on ChromeOS.

chromeos/dbus/debug_daemon_client.h

Index: chromeos/dbus/debug_daemon_client.h
diff --git a/chromeos/dbus/debug_daemon_client.h b/chromeos/dbus/debug_daemon_client.h
index 803500d489e26504c2bc678e1b8f87be98bc084a..53906bc23b30261d920b27dfa995439fae9acd74 100644
--- a/chromeos/dbus/debug_daemon_client.h
+++ b/chromeos/dbus/debug_daemon_client.h
@@ -192,6 +192,16 @@ class CHROMEOS_EXPORT DebugDaemonClient
   virtual void WaitForServiceToBeAvailable(
       const WaitForServiceToBeAvailableCallback& callback) = 0;
 
+  // A callback for SetOOmScoreAdj().

[hashimoto, 2016/08/15 03:54:23]

nit: s/OOm/Oom/

[cylee1, 2016/08/16 19:47:11]

Done.

+  typedef base::Callback<void(bool success, const std::string& output)>
+      SetOomScoreAdjCallback;
+
+  // Set OOM score oom_score_adj for some process.
+  // Note that the API only permits setting OOM score for processes running by

[hashimoto, 2016/08/15 03:54:23]

Please make it clear what "the API" here means. (is it debugd's API, or this
class's?)

[cylee1, 2016/08/16 19:47:11]

Done.

+  // chronos or Android apps.
+  virtual void SetOomScoreAdj(const std::map<int, int>& pairs,

[hashimoto, 2016/08/15 03:54:23]

From the name "pairs", it's not clear what the values in this map mean.
Please give this argument a more descriptive name (e.g. pid_to_oom_score_adj)

[cylee1, 2016/08/16 19:47:11]

Done.

+                              const SetOomScoreAdjCallback& callback) = 0;
+
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
   static DebugDaemonClient* Create();