chromeos: call GetIdleTime from power manager client

chrome/browser/chromeos/dbus/power_manager_client.h

Index: chrome/browser/chromeos/dbus/power_manager_client.h
diff --git a/chrome/browser/chromeos/dbus/power_manager_client.h b/chrome/browser/chromeos/dbus/power_manager_client.h
index 11ecf90dac6c65f750ebb0c7f35544c30a34a427..b7d8bf0f5e7a1e64aba7c7c36d8b99a4adaf995d 100644
--- a/chrome/browser/chromeos/dbus/power_manager_client.h
+++ b/chrome/browser/chromeos/dbus/power_manager_client.h
@@ -5,6 +5,7 @@
 #ifndef CHROME_BROWSER_CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 #define CHROME_BROWSER_CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 
@@ -36,6 +37,8 @@ struct PowerSupplyStatus {
   const std::string& ToString() const;
 };
 
+typedef base::Callback<void(int64_t)> CalculateIdleTimeCallback;

[satorux1, 2011/11/15 00:57:42]

Please add some comment about the parameter: int64_t.

[Simon Que, 2011/11/15 01:29:38]

Done.

+
 // PowerManagerClient is used to communicate with the power manager.
 class PowerManagerClient {
  public:
@@ -72,6 +75,10 @@ class PowerManagerClient {
   // Requests shutdown of the system.
   virtual void RequestShutdown() = 0;
 
+  // Calculates idle time asynchronously. If it encounters some error,
+  // it returns -1.

[satorux1, 2011/11/15 00:57:42]

The comment is misleading. It's a void function. You can say something like

If it encounters some error, -1 is passed to |callback|.

BTW, on success, what value is passed? Please also document.

[Simon Que, 2011/11/15 01:29:38]

Done.

+  virtual void CalculateIdleTime(CalculateIdleTimeCallback* callback) = 0;

[satorux1, 2011/11/15 00:57:42]

This shouldn't have to be a pointer. Please remove *, and fix the caller.

[Simon Que, 2011/11/15 01:29:38]

Done.

+
   // Creates the instance.
   static PowerManagerClient* Create(dbus::Bus* bus);