chromeos: power: Refactor RendererFreezer and add tests

chromeos/dbus/fake_power_manager_client.h

Index: chromeos/dbus/fake_power_manager_client.h
diff --git a/chromeos/dbus/fake_power_manager_client.h b/chromeos/dbus/fake_power_manager_client.h
index f4b9af59b45a6978d0370ca647a628335312bf01..9fc9a4dc77b883a8c65d5547585fb213e1bf7ed4 100644
--- a/chromeos/dbus/fake_power_manager_client.h
+++ b/chromeos/dbus/fake_power_manager_client.h
@@ -67,6 +67,10 @@ class FakePowerManagerClient : public PowerManagerClient {
   void SendPowerButtonEvent(bool down, const base::TimeTicks& timestamp);
 
  private:
+  // Callback that will be run by asynchronous suspend delays to report
+  // readiness.
+  void HandleSuspendReadiness();
+
   ObserverList<Observer> observers_;
 
   // Last policy passed to SetPolicy().
@@ -78,6 +82,9 @@ class FakePowerManagerClient : public PowerManagerClient {
   int num_set_policy_calls_;
   int num_set_is_projecting_calls_;
 
+  // Number of pending suspend readiness callbacks.
+  int num_pending_suspend_readiness_callbacks_;
+
   // Last projecting state set in SetIsProjecting().
   bool is_projecting_;