Tag some of Mojo heap allocations for the heap profiler.

mojo/edk/system/multiprocess_message_pipe_unittest.cc

 // Copyright 2013 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 <stdio.h>
 #include <string.h>
 
 #include <string>
@@ skipping 1294 matching lines @@
 
   // Wait on handle 0 using MojoWait.
   EXPECT_EQ(MOJO_RESULT_OK, MojoWait(handles[0], MOJO_HANDLE_SIGNAL_PEER_CLOSED,
                                      MOJO_DEADLINE_INDEFINITE, nullptr));
 
   base::MessageLoop message_loop;
 
   // Wait on handle 1 using a Watcher.
   {
     base::RunLoop run_loop;
-    Watcher watcher;
+    Watcher watcher(FROM_HERE);
     watcher.Start(Handle(handles[1]), MOJO_HANDLE_SIGNAL_PEER_CLOSED,
                   base::Bind([] (base::RunLoop* loop, MojoResult result) {
                     EXPECT_EQ(MOJO_RESULT_OK, result);
                     loop->Quit();
                   }, &run_loop));
     run_loop.Run();
   }
 
   // Wait on handle 2 by polling with MojoReadMessage.
   MojoResult result;
@@ skipping 95 matching lines @@
 INSTANTIATE_TEST_CASE_P(
     ,
     MultiprocessMessagePipeTestWithPeerSupport,
     testing::Values(test::MojoTestBase::LaunchType::CHILD,
                     test::MojoTestBase::LaunchType::PEER,
                     test::MojoTestBase::LaunchType::NAMED_CHILD,
                     test::MojoTestBase::LaunchType::NAMED_PEER));
 }  // namespace
 }  // namespace edk
 }  // namespace mojo