shill: Add metrics Network.Shill.TimeToDrop and Network.Shill.*.TimeOnline

Also changed some existing constant names for consistency purposes.

BUG=chromium-os:24810
TEST=Unit tests, network_WiFiManager (7/9)

Change-Id: I49db32dc0a4b6b80a5114b910b9be6e45a30d7f0
Reviewed-on: https://gerrit.chromium.org/gerrit/13883
Commit-Ready: Thieu Le <thieule@chromium.org>
Reviewed-by: Thieu Le <thieule@chromium.org>
Tested-by: Thieu Le <thieule@chromium.org>
diff --git a/manager.h b/manager.h
index 38a418f..96c2c21 100644
--- a/manager.h
+++ b/manager.h
@@ -27,7 +27,6 @@
 class ControlInterface;
 class Error;
 class EventDispatcher;
-class GLib;
 class ManagerAdaptorInterface;
 class Metrics;
 
@@ -172,6 +171,9 @@
   void SortServices();
   bool MatchProfileWithService(const ServiceRefPtr &service);
 
+  // For unit testing.
+  void set_metrics(Metrics *metrics) { metrics_ = metrics; }
+
   EventDispatcher *dispatcher_;
   ScopedRunnableMethodFactory<Manager> task_factory_;
   const FilePath run_path_;