Expose signing key from cloud policy stores

chrome/browser/chromeos/policy/device_local_account_policy_store.h

Index: chrome/browser/chromeos/policy/device_local_account_policy_store.h
diff --git a/chrome/browser/chromeos/policy/device_local_account_policy_store.h b/chrome/browser/chromeos/policy/device_local_account_policy_store.h
index 63c81ecc959735dbf40778884ecd42d901573cc7..56a75c7f194de7dcdd6f805bf73442c5944fa7ab 100644
--- a/chrome/browser/chromeos/policy/device_local_account_policy_store.h
+++ b/chrome/browser/chromeos/policy/device_local_account_policy_store.h
@@ -21,7 +21,6 @@ class SequencedTaskRunner;
 }
 
 namespace chromeos {
-class DeviceSettingsService;
 class SessionManagerClient;
 }
 
@@ -36,7 +35,8 @@ class DeviceLocalAccountPolicyBroker;
 // CloudPolicyStore implementation for device-local account policy. Stores/loads
 // policy to/from session_manager.
 class DeviceLocalAccountPolicyStore
-    : public UserCloudPolicyStoreBase {
+    : public UserCloudPolicyStoreBase,
+      public chromeos::DeviceSettingsService::Observer {
  public:
   DeviceLocalAccountPolicyStore(
       const std::string& account_id,
@@ -52,6 +52,12 @@ class DeviceLocalAccountPolicyStore
   void Load() override;
 
  private:
+  // chromeos::DeviceSettingsService::Observer:
+  void DeviceSettingsUpdated() override;
+
+  // Updates state from the device settings service.
+  void UpdateFromDeviceSettingsService();
+
   // Called back by |session_manager_client_| after policy retrieval. Checks for
   // success and triggers policy validation.
   void ValidateLoadedPolicyBlob(const std::string& policy_blob);