Change userid from a uint32_t to a string guid

mojo/shell/public/cpp/application_test_base.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_SHELL_PUBLIC_CPP_APPLICATION_TEST_BASE_H_
 #define MOJO_SHELL_PUBLIC_CPP_APPLICATION_TEST_BASE_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/bindings/array.h"
 #include "mojo/public/cpp/bindings/string.h"
@@ skipping 16 matching lines @@
 
 // Used to configure the ShellConnection. This is used internally by
 // ApplicationTestBase, but useful if you do not want to subclass
 // ApplicationTestBase.
 class TestHelper {
  public:
   explicit TestHelper(ShellClient* client);
   ~TestHelper();
 
   Connector* connector() { return shell_connection_->connector(); }
-  std::string test_name() { return name_; }
+  const std::string& test_name() { return name_; }
+  const std::string& test_userid() { return userid_; }
   uint32_t test_instance_id() { return instance_id_; }
-  uint32_t test_userid() { return userid_; }
 
  private:
   // The application delegate used if GetShellClient is not overridden.
   ShellClient default_shell_client_;
 
   // The application implementation instance, reconstructed for each test.
   scoped_ptr<ShellConnection> shell_connection_;
 
   std::string name_;
+  std::string userid_;
   uint32_t instance_id_;
-  uint32_t userid_;
 
   DISALLOW_COPY_AND_ASSIGN(TestHelper);
 };
 
 // A GTEST base class for application testing executed in mojo_shell.
 class ApplicationTestBase : public testing::Test {
  public:
   ApplicationTestBase();
   ~ApplicationTestBase() override;
 
  protected:
   Connector* connector() {
     return test_helper_ ? test_helper_->connector() : nullptr;
   }
-  std::string test_name() const {
-    return test_helper_ ? test_helper_->test_name() : std::string();
+  const std::string& test_name() const {
+    return test_helper_ ? test_helper_->test_name() : empty_;
+  }
+  const std::string& test_userid() const {
+    return test_helper_ ? test_helper_->test_userid() : inherit_user_id_;
   }
   uint32_t test_instance_id() const {
     return test_helper_ ? test_helper_->test_instance_id() :
         shell::mojom::Connector::kInvalidApplicationID;
   }
-  uint32_t test_userid() const {
-    return test_helper_ ? test_helper_->test_userid() :
-        shell::mojom::Connector::kUserInherit;
-  }
 
   // Get the ShellClient for the application to be tested.
   virtual ShellClient* GetShellClient();
 
   // testing::Test:
   void SetUp() override;
   void TearDown() override;
 
   // True by default, which indicates a MessageLoop will automatically be
   // created for the application.  Tests may override this function to prevent
   // a default loop from being created.
   virtual bool ShouldCreateDefaultRunLoop();
 
  private:
   scoped_ptr<TestHelper> test_helper_;
+  std::string empty_;
+  std::string inherit_user_id_ = shell::mojom::kInheritUserID;
 
   DISALLOW_COPY_AND_ASSIGN(ApplicationTestBase);
 };
 
 }  // namespace test
 
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_PUBLIC_CPP_APPLICATION_TEST_BASE_H_