All DCP manager tests that enroll/register are tested with all auths.

components/policy/core/common/cloud/mock_signing_service.h

Index: components/policy/core/common/cloud/mock_signing_service.h
diff --git a/components/policy/core/common/cloud/mock_signing_service.h b/components/policy/core/common/cloud/mock_signing_service.h
index beb3f092e33bffe9027036da052b0c3c8af732ba..d8024f3a1c7a4d8e2902d9e20639935a774253b0 100644
--- a/components/policy/core/common/cloud/mock_signing_service.h
+++ b/components/policy/core/common/cloud/mock_signing_service.h
@@ -17,19 +17,17 @@ class FakeSigningService : public SigningService {
   FakeSigningService();
   virtual ~FakeSigningService();
 
-  void SignRegistrationData(
-      const enterprise_management::CertificateBasedDeviceRegistrationData*
-          registration_data,
-      enterprise_management::SignedData* signed_data);
-
   void SignData(const std::string& data, const SigningCallback& callback)
       override;
 
+  // Useful for test setups without having to deal with callbacks.
+  void SignDataSynchronously(const std::string& data,
+      enterprise_management::SignedData* signed_data);
+
+  // Determine whether SignData will appear successful or not.
   void set_success(bool success);
- private:
-  void DoSignData(const std::string& data,
-                         enterprise_management::SignedData* signed_data);
 
+ private:
   bool success_ = true;
 };