Refresh policies from DM server periodically

chrome/browser/policy/device_token_fetcher.h

Index: chrome/browser/policy/device_token_fetcher.h
diff --git a/chrome/browser/policy/device_token_fetcher.h b/chrome/browser/policy/device_token_fetcher.h
index 7704d35cdc0c4391fbba84be422896a6ed321de8..91ef3b2c5c10484aad667d655a206738bb8fd7d1 100644
--- a/chrome/browser/policy/device_token_fetcher.h
+++ b/chrome/browser/policy/device_token_fetcher.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/file_path.h"
+#include "base/observer_list.h"
 #include "base/ref_counted.h"
 #include "base/waitable_event.h"
 #include "chrome/browser/policy/device_management_backend.h"
@@ -31,6 +32,13 @@ class DeviceTokenFetcher
       public DeviceManagementBackend::DeviceRegisterResponseDelegate,
       public base::RefCountedThreadSafe<DeviceTokenFetcher> {
  public:
+  class Observer {
+   public:
+    virtual void OnTokenSuccess() = 0;
+    virtual void OnTokenError() = 0;
+    virtual ~Observer() {}
+  };
+
   // Requests to the device management server are sent through |backend|. It
   // obtains the authentication token from |token_service|. The fetcher stores
   // the device token to |token_path| once it's retrieved from the server.
@@ -49,6 +57,9 @@ class DeviceTokenFetcher
       const em::DeviceRegisterResponse& response);
   virtual void OnError(DeviceManagementBackend::ErrorCode code);
 
+  // Re-initializes this DeviceTokenFetcher
+  void Restart();
+
   // Called by subscribers of the device management token to indicate that they
   // will need the token in the future. Must be called on the UI thread.
   void StartFetching();
@@ -76,6 +87,14 @@ class DeviceTokenFetcher
   // True if the device token has been fetched and is valid.
   bool IsTokenValid() const;
 
+  void AddObserver(Observer* obs) {
+    observer_list_.AddObserver(obs);
+  }
+
+  void RemoveObserver(Observer* obs) {
+    observer_list_.RemoveObserver(obs);
+  }
+
  private:
   friend class DeviceTokenFetcherTest;
 
@@ -114,6 +133,14 @@ class DeviceTokenFetcher
   // available.
   void SendServerRequestIfPossible();
 
+  void NotifyTokenSuccess() {
+    FOR_EACH_OBSERVER(Observer, observer_list_, OnTokenSuccess());
+  }
+
+  void NotifyTokenError() {
+    FOR_EACH_OBSERVER(Observer, observer_list_, OnTokenError());
+  }
+
   // Saves the device management token to disk once it has been retrieved from
   // the server. Must be called on the FILE thread.
   static void WriteDeviceTokenToDisk(const FilePath& path,
@@ -124,6 +151,7 @@ class DeviceTokenFetcher
   // management server and generate the device token.
   static std::string GenerateNewDeviceID();
 
+  ObserverList<Observer> observer_list_;
   FilePath token_path_;
   DeviceManagementBackend* backend_;  // weak
   TokenService* token_service_;