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

chromeos/dbus/debug_daemon_client.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 CHROMEOS_DBUS_DEBUG_DAEMON_CLIENT_H_
 #define CHROMEOS_DBUS_DEBUG_DAEMON_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 174 matching lines @@
   virtual void UploadCrashes() = 0;
 
   // A callback for WaitForServiceToBeAvailable().
   typedef base::Callback<void(bool service_is_ready)>
       WaitForServiceToBeAvailableCallback;
 
   // Runs the callback as soon as the service becomes available.
   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();
 
  protected:
   // Create() should be used instead.
   DebugDaemonClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DebugDaemonClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_DEBUG_DAEMON_CLIENT_H_