Handle exception writing to Chromoting host's stdin.

Handle exception writing to Chromoting host's stdin.

The linux_me2me_host script launches the host process, then writes the
JSON config to the child's stdin. If the host process dies before the
data is written to stdin, an IOError (EPIPE) exception is raised. This
CL handles the exception and retries launching the host, instead of
exiting the script.

To test this, I added a time.sleep(5) call between launching the
host and writing the config to stdin. This allowed me enough time to
simulate the error by killing the host process.

BUG=473441
Committed: https://crrev.com/acfbcb214d2af95cdc8e0e16b809db8fde878494
Cr-Commit-Position: refs/heads/master@{#329273}

[Lambros, 2015-05-09 01:05:14]

lambroslambrou@chromium.org changed reviewers:
+ sergeyu@chromium.org

[Sergey Ulanov, 2015-05-09 01:29:23]

lgtm

[Sergey Ulanov, 2015-05-09 01:29:41]

The CQ bit was checked by sergeyu@chromium.org

[commit-bot: I haz the power, 2015-05-09 01:42:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1138613002/1

[commit-bot: I haz the power, 2015-05-09 05:50:27]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-09 05:50:29]

Try jobs failed on following builders:
  android_chromium_gn_compile_dbg on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  android_chromium_gn_compile_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  cast_shell_android on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  cast_shell_linux on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  chromium_presubmit on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  linux_chromium_asan_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_chromeos_compile_dbg_ng on tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_clobber_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_gn_dbg on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  linux_chromium_gn_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_TIMED_OUT, no build
URL)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_TIMED_OUT, no build URL)
  win_chromium_compile_dbg_ng on tryserver.chromium.win (JOB_TIMED_OUT, no build
URL)
  win_chromium_rel_ng on tryserver.chromium.win (JOB_TIMED_OUT, no build URL)
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_TIMED_OUT, no build
URL)

[Lambros, 2015-05-11 23:06:18]

The CQ bit was checked by lambroslambrou@chromium.org

[commit-bot: I haz the power, 2015-05-11 23:06:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1138613002/1

[commit-bot: I haz the power, 2015-05-11 23:43:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-11 23:45:24]

Patchset 1 (id:??) landed as
https://crrev.com/acfbcb214d2af95cdc8e0e16b809db8fde878494
Cr-Commit-Position: refs/heads/master@{#329273}