Enable ThreadChecker in non-debug builds if DCHECK_ALWAYS_ON is

base/message_pump_libevent_unittest.cc

Index: base/message_pump_libevent_unittest.cc
diff --git a/base/message_pump_libevent_unittest.cc b/base/message_pump_libevent_unittest.cc
index 9ec78de587d31f73ca4873a02713e4380fd91826..92531fd67d0ec28dfa9a61f76d3ed77cb7d0662c 100644
--- a/base/message_pump_libevent_unittest.cc
+++ b/base/message_pump_libevent_unittest.cc
@@ -59,7 +59,7 @@ class StupidWatcher : public MessagePumpLibevent::Watcher {
   virtual void OnFileCanWriteWithoutBlocking(int fd) {}
 };
 
-#if GTEST_HAS_DEATH_TEST
+#if GTEST_HAS_DEATH_TEST && !defined(NDEBUG)

[Nico, 2012/01/02 23:42:37]

Isn't this now also a test that won't fail on the (rel) trybots?

[Jói, 2012/01/04 09:29:32]

True, but it's also a test that's not likely to break.

The options here seem to be:
a) Leave it as is;
b) Remove the test altogether (easiest, but it's not an empty test, it tests
that ThreadChecker is used correctly in this class);
c) Use the same preprocessor sequence here as in ThreadChecker, i.e.
!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) (some code duplication)
d) Expose ENABLE_THREAD_CHECKER to users of base/threading/thread_checker.h and
use it here;
e) Bring back the IsEnabled thing I had in a previous patch set.

I would propose either (a) or (d).  I'm no longer a fan of (e) since what you
really need is a preprocessor check rather than an at-runtime check, plus (e) is
slightly more complex.

[Nico, 2012/01/04 16:15:11]

Famous last words :-)
(Saying both "safe, because unlikely to break" and "can't remove this test, it
checks something important" sounds a bit contradictory to me :-) )
f) Turn the thread checker check into a CHECK() (right?)

But ok, let's go with (a) for now and see how it goes. LGTM.

 
 // Test to make sure that we catch calling WatchFileDescriptor off of the
 // wrong thread.
@@ -67,13 +67,13 @@ TEST_F(MessagePumpLibeventTest, TestWatchingFromBadThread) {
   MessagePumpLibevent::FileDescriptorWatcher watcher;
   StupidWatcher delegate;
 
-  ASSERT_DEBUG_DEATH(io_loop()->WatchFileDescriptor(
+  ASSERT_DEATH(io_loop()->WatchFileDescriptor(
       STDOUT_FILENO, false, MessageLoopForIO::WATCH_READ, &watcher, &delegate),
       "Check failed: "
       "watch_file_descriptor_caller_checker_.CalledOnValidThread()");
 }
 
-#endif  // GTEST_HAS_DEATH_TEST
+#endif  // GTEST_HAS_DEATH_TEST && !defined(NDEBUG)
 
 class DeleteWatcher : public MessagePumpLibevent::Watcher {
  public: