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..d9867f5461d113b1214d3db97efe80069fdf5bc7 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;
 }
 
@@ -35,8 +34,7 @@ class DeviceLocalAccountPolicyBroker;
 
 // CloudPolicyStore implementation for device-local account policy. Stores/loads
 // policy to/from session_manager.
-class DeviceLocalAccountPolicyStore
-    : public UserCloudPolicyStoreBase {
+class DeviceLocalAccountPolicyStore : public UserCloudPolicyStoreBase {
  public:
   DeviceLocalAccountPolicyStore(
       const std::string& account_id,