Remove support for Root identity singletons and rely on the all_users bit to be set. + test

mojo/shell/tests/connect/connect_unittest.cc

 // Copyright 2016 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.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 334 matching lines @@
   Identity result_identity;
   {
     base::RunLoop loop;
     client_process_test->LaunchAndConnectToProcess(
         base::Bind(&ReceiveConnectionResult, &result, &result_identity, &loop));
     loop.Run();
   }
   EXPECT_EQ(shell::mojom::ConnectResult::ACCESS_DENIED, result);
 }
 
+// Verifies that a client with the "all_users" capability class can receive
+// connections from clients run as other users.
+TEST_F(ConnectTest, AllUsersSingleton) {
+  // Connect to an instance with an explicitly different user_id.
+  const std::string singleton_userid = base::GenerateGUID();
+  Connector::ConnectParams params(Identity(kTestAppName, singleton_userid));
+  scoped_ptr<Connection> connection = connector()->Connect(&params);
+  {
+    base::RunLoop loop;
+    connection->AddConnectionCompletedClosure(base::Bind(&QuitLoop, &loop));
+    loop.Run();
+    EXPECT_EQ(connection->GetRemoteIdentity().user_id(), singleton_userid);
+  }
+  // This connects using the current client's user_id, but should be bound to
+  // the instance run as |singleton_userid|.
+  scoped_ptr<Connection> inherit_connection =
+      connector()->Connect(kTestAppName);
+  {
+    base::RunLoop loop;
+    inherit_connection->AddConnectionCompletedClosure(
+        base::Bind(&QuitLoop, &loop));
+    loop.Run();
+    EXPECT_EQ(connection->GetRemoteIdentity().user_id(), singleton_userid);
+  }
+}
+
 // Tests that we can expose an interface to targets on outbound connections.
 TEST_F(ConnectTest, LocalInterface) {
   // Connect to a standalone application.
   {
     test::mojom::ConnectTestServicePtr service;
     scoped_ptr<Connection> connection = connector()->Connect(kTestAppName);
     connection->GetInterface(&service);
     connection->AddInterface<test::mojom::ExposedInterface>(this);
 
     uint32_t remote_id = shell::mojom::kInvalidInstanceID;
@@ skipping 46 matching lines @@
       CompareConnectionState(
           kTestAppAName, test_name(), test_userid(), test_instance_id(),
           kTestAppAName, connection->GetRemoteIdentity().user_id(), remote_id);
     }
 
   }
 }
 
 }  // namespace shell
 }  // namespace mojo