Also adjust the event handler's timer_fd to the monotonic clock.
Also adjust the event handler's timer_fd to the monotonic clock.

Should fix timeouts on pkg-linux-debug-be.

Cf. 9387fead15f6158abc502702d0091c355d69dec3.

BUG=http://dartbug.com/25055
BUG=http://dartbug.com/25216
TBR=iposva@google.com

Review URL: https://codereview.chromium.org/1513843007 .

dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk