Mojo: Base our epsilon timeouts off of TestTimeouts::tiny_timeout().

mojo/system/test_utils.cc

Index: mojo/system/test_utils.cc
diff --git a/mojo/system/test_utils.cc b/mojo/system/test_utils.cc
index 1ff080be4cd815d030e44e3b2278585ff24c07d6..e19fe3505660320ea2307c7c7179a563047fae22 100644
--- a/mojo/system/test_utils.cc
+++ b/mojo/system/test_utils.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/test_timeouts.h"
 
 namespace mojo {
 namespace system {
@@ -31,6 +32,14 @@ void PostTaskAndWait(scoped_refptr<base::TaskRunner> task_runner,
   event.Wait();
 }
 
+base::TimeDelta EpsilonTimeout() {
+  // Originally, our epsilon timeout was 10 ms, which was mostly fine but flaky
+  // on some Windows bots. So I bumped it up to 30 ms, which made things
+  // reliable. Currently, |tiny_timeout()| is 100 ms, which means that this will
+  // be 25 ms, which will hopefully be okay.
+  return TestTimeouts::tiny_timeout() / 4;
+}
+
 // TestIOThread ----------------------------------------------------------------
 
 TestIOThread::TestIOThread(Mode mode)