Update NetworkStateNotifier to use message_center.

ash/system/chromeos/network/network_observer.h

Index: ash/system/chromeos/network/network_observer.h
diff --git a/ash/system/chromeos/network/network_observer.h b/ash/system/chromeos/network/network_observer.h
index cff0c692ff3ac04a71b45038e6f180512744ea99..20473c7786c416f3e2fcb2ec3ab3eda4406c7ad9 100644
--- a/ash/system/chromeos/network/network_observer.h
+++ b/ash/system/chromeos/network/network_observer.h
@@ -9,59 +9,16 @@
 
 #include "base/strings/string16.h"
 
-namespace chromeos {
-class NetworkState;
-}
-
 namespace ash {
 
-struct NetworkIconInfo;
-class NetworkTrayDelegate;
-
 class NetworkObserver {
  public:
-  enum MessageType {
-    // Priority order, highest to lowest.
-    ERROR_CONNECT_FAILED,
-    ERROR_OUT_OF_CREDITS,
-    MESSAGE_DATA_PROMO,
-  };
-
-  enum NetworkType {
-    // ash relevant subset of network_constants.h connection type.
-    NETWORK_ETHERNET,
-    NETWORK_CELLULAR,
-    NETWORK_CELLULAR_LTE,
-    NETWORK_WIFI,
-    NETWORK_BLUETOOTH,
-    NETWORK_UNKNOWN,
-  };
-
   virtual ~NetworkObserver() {}
 
-  // Sets a network message notification.
-  // |message_type| identifies the type of message.
-  // |network_type| identifies the type of network involved.
-  // |delegate|->NotificationLinkClicked() will be called if any of the
-  // |links| are clicked (if supplied, |links| may be empty).
-  virtual void SetNetworkMessage(NetworkTrayDelegate* delegate,
-                                 MessageType message_type,
-                                 NetworkType network_type,
-                                 const base::string16& title,
-                                 const base::string16& message,
-                                 const std::vector<base::string16>& links) = 0;
-
-  // Clears the message notification for |message_type|.
-  virtual void ClearNetworkMessage(MessageType message_type) = 0;
-
   // Called to request toggling Wi-Fi enable/disable, e.g. from an accelerator.
   // NOTE: Toggling is asynchronous and subsequent calls to query the current
   // state may return the old value.
   virtual void RequestToggleWifi() = 0;
-
-  // Helper function to get the network type from NetworkState.
-  static NetworkType GetNetworkTypeForNetworkState(
-      const chromeos::NetworkState* network);
 };
 
 }  // namespace ash