message: Attempt to deflake StdioFileSystemTest.TestLockBumping
  Saw another instance of the flake:
diff: @@ -518,14 +518,14 @@ void FileSystemTest::TestLockBumping() {
  EXPECT_FALSE(file_system()->TryLockWithTimeout(
  lock_name, Timer::kSecondMs * 3, timer(), &handler_).is_true());
  + // Bump the lock again to deflake this test on the CI vm.
  + EXPECT_TRUE(file_system()->BumpLockTimeout(lock_name, &handler_));
  +
  // Sleep 2s. We still hold the lock, because we bumped it.
  timer()->SleepMs(Timer::kSecondMs * 2);
  // Try to take the lock again. If bumping didn't work, then the lock would
  // have expired 1s ago and we could have taken it here.
  - // TODO(oschaaf): I have observed this flaking a single time during release
  - // test execution. We should look into bumping the timeouts here if it happens
  - // again.
  EXPECT_FALSE(file_system()->TryLockWithTimeout(
  lock_name, Timer::kSecondMs * 3, timer(), &handler_).is_true());
  