EDK: Add a mojo::test::SimpleTestThread (and use it).

mojo/edk/system/waiter_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.
 
 // NOTE(vtl): Some of these tests are inherently flaky (e.g., if run on a
 // heavily-loaded system). Sorry. |test::EpsilonDeadline()| may be increased to
 // increase tolerance and reduce observed flakiness (though doing so reduces the
 // meaningfulness of the test).
 
 #include "mojo/edk/system/waiter.h"
 
 #include <stdint.h>
 
-#include "base/threading/simple_thread.h"
 #include "mojo/edk/system/mutex.h"
 #include "mojo/edk/system/test_utils.h"
+#include "mojo/edk/test/simple_test_thread.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace system {
 namespace {
 
 const unsigned kPollTimeMs = 10;
 
-class WaitingThread : public base::SimpleThread {
+class WaitingThread : public mojo::test::SimpleTestThread {
  public:
   explicit WaitingThread(MojoDeadline deadline)
-      : base::SimpleThread("waiting_thread"),
-        deadline_(deadline),
+      : deadline_(deadline),
         done_(false),
         result_(MOJO_RESULT_UNKNOWN),
         context_(static_cast<uint32_t>(-1)) {
     waiter_.Init();
   }
 
   ~WaitingThread() override { Join(); }
 
   void WaitUntilDone(MojoResult* result,
                      uint32_t* context,
@@ skipping 248 matching lines @@
     EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, result);
     EXPECT_EQ(7u, context);
     EXPECT_GT(elapsed, (1 - 1) * test::EpsilonDeadline());
     EXPECT_LT(elapsed, (1 + 1) * test::EpsilonDeadline());
   }
 }
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo