Add ScopedStubEnterpriseInstallAttributes for tests to set test install attributes.

chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h

Index: chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h
diff --git a/chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h b/chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h
index 2ddccecfc17be367d3366eaabfca857e9d519f26..88f7bbebe102d5b5040724aaed73bd9690118d79 100644
--- a/chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h
+++ b/chrome/browser/chromeos/policy/stub_enterprise_install_attributes.h
@@ -29,6 +29,17 @@ class StubEnterpriseInstallAttributes : public EnterpriseInstallAttributes {
   DISALLOW_COPY_AND_ASSIGN(StubEnterpriseInstallAttributes);
 };
 
+// Helper class to set enterprise install attributes in the scope of a test.
+// Note: The install attributes cannot be removed once set, so the instance sets
+// the attributes on construction, but does not remove them on destruction.
+class ScopedStubEnterpriseInstallAttributes {
+ public:
+  ScopedStubEnterpriseInstallAttributes(const std::string& domain,
+                                        const std::string& registration_user,
+                                        const std::string& device_id,
+                                        DeviceMode mode);
+};
+
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_STUB_ENTERPRISE_INSTALL_ATTRIBUTES_H_