Linux sandbox: add basic Yama support

sandbox/linux/services/thread_helpers_unittests.cc

 // 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.
 
 #include "sandbox/linux/services/thread_helpers.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ skipping 46 matching lines @@
 #define MAYBE_IsSingleThreadedStartAndStop DISABLED_IsSingleThreadedStartAndStop
 #else
 #define MAYBE_IsSingleThreadedBasic IsSingleThreadedBasic
 #define MAYBE_IsSingleThreadedIterated IsSingleThreadedIterated
 #define MAYBE_IsSingleThreadedStartAndStop IsSingleThreadedStartAndStop
 #endif
 
 TEST(ThreadHelpers, MAYBE_IsSingleThreadedBasic) {
   ScopedProcSelfTask task;
   ASSERT_TRUE(ThreadHelpers::IsSingleThreaded(task.fd()));
+  ASSERT_TRUE(ThreadHelpers::IsSingleThreaded(-1));
 
   base::Thread thread("sandbox_tests");
   ASSERT_TRUE(thread.Start());
   ASSERT_FALSE(ThreadHelpers::IsSingleThreaded(task.fd()));
+  ASSERT_FALSE(ThreadHelpers::IsSingleThreaded(-1));
   // Explicitly stop the thread here to not pollute the next test.
   ASSERT_TRUE(ThreadHelpers::StopThreadAndWatchProcFS(task.fd(), &thread));
 }
 
 TEST(ThreadHelpers, MAYBE_IsSingleThreadedIterated) {
   ScopedProcSelfTask task;
   ASSERT_TRUE(ThreadHelpers::IsSingleThreaded(task.fd()));
 
   // Iterate to check for race conditions.
   for (int i = 0; i < GetRaceTestIterations(); ++i) {
@@ skipping 18 matching lines @@
 
     ASSERT_TRUE(ThreadHelpers::StopThreadAndWatchProcFS(task.fd(), &thread));
     ASSERT_TRUE(ThreadHelpers::IsSingleThreaded(task.fd()));
     ASSERT_EQ(1, base::GetNumberOfThreads(base::GetCurrentProcessHandle()));
   }
 }
 
 }  // namespace
 
 }  // namespace sandbox