chromeos: Move EnableScreenLock to PowerManagerClient from PowerLibrary

chrome/browser/chromeos/cros/power_library.h

Index: chrome/browser/chromeos/cros/power_library.h
diff --git a/chrome/browser/chromeos/cros/power_library.h b/chrome/browser/chromeos/cros/power_library.h
index a5aa285e718d800a12ff663e10729a0c7b790212..d732ef6923f807189f284380e4ab12a79fc7f4ad 100644
--- a/chrome/browser/chromeos/cros/power_library.h
+++ b/chrome/browser/chromeos/cros/power_library.h
@@ -32,9 +32,6 @@ class PowerLibrary {
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
 
-  // Enable/disable screen lock for current session.
-  virtual void EnableScreenLock(bool enable) = 0;
-
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via CrosLibrary::Get().
   static PowerLibrary* GetImpl(bool stub);