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

chromeos/dbus/debug_daemon_client.cc

Index: chromeos/dbus/debug_daemon_client.cc
diff --git a/chromeos/dbus/debug_daemon_client.cc b/chromeos/dbus/debug_daemon_client.cc
index a101518c25c9f8b63de30690151ec216eaaaf844..10ab9bf7e09a0c1c0ffccd689957915c9f0d50bd 100644
--- a/chromeos/dbus/debug_daemon_client.cc
+++ b/chromeos/dbus/debug_daemon_client.cc
@@ -460,6 +460,31 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
     debugdaemon_proxy_->WaitForServiceToBeAvailable(callback);
   }
 
+  void SetOomScoreAdj(const std::map<int, int>& scores,
+                      const SetOomScoreAdjCallback& callback) override {
+    dbus::MethodCall method_call(debugd::kDebugdInterface,
+                                 debugd::kSetOomScoreAdj);
+    dbus::MessageWriter writer(&method_call);
+    dbus::MessageWriter sub_writer(NULL);

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

Please declare this variable in as local a scope as possible, and as close to
the first use as possible.
(https://google.github.io/styleguide/cppguide.html#Local_Variables)

Also, please use nullptr.

[cylee1, 2016/08/16 19:47:10]

Done.

+    dbus::MessageWriter elem_writer(NULL);

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

ditto.

[cylee1, 2016/08/16 19:47:10]

Done.

+
+    writer.OpenArray("{ii}", &sub_writer);
+    for (const auto& entry : scores) {
+      sub_writer.OpenDictEntry(&elem_writer);
+      elem_writer.AppendInt32(entry.first);
+      elem_writer.AppendInt32(entry.second);
+      sub_writer.CloseContainer(&elem_writer);
+    }
+    writer.CloseContainer(&sub_writer);
+
+    debugdaemon_proxy_->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&DebugDaemonClientImpl::OnSetOomScoreAdj,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   callback));
+  }
+
  protected:
   void Init(dbus::Bus* bus) override {
     debugdaemon_proxy_ =
@@ -720,6 +745,18 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
     pipe_reader_.reset();
   }
 
+  void OnSetOomScoreAdj(const SetOomScoreAdjCallback& callback,
+                        dbus::Response* response) {
+    if (callback.is_null())

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

Is there any strong reason to allow null callbacks?
If not, please remove this code.

[cylee1, 2016/08/16 19:47:10]

Done.

+      return;
+
+    std::string output;
+    if (response && dbus::MessageReader(response).PopString(&output))
+      callback.Run(true, output);
+    else
+      callback.Run(false, "");
+  }
+
   dbus::ObjectProxy* debugdaemon_proxy_;
   std::unique_ptr<PipeReaderForString> pipe_reader_;
   StopAgentTracingCallback callback_;