Add checks for READMEs for each virtual test suite.

Add checks for READMEs for each virtual test suite.

By convention, each virtual test suite should have a README.txt documenting
what directory it mirrors and what command line args are needed, so that
you can tell what an "empty" directory under LayoutTests/ is for.

This patch modifies lint-test-expectations to check that those READMEs
exist, and will help avoid the possibility that we'll delete whole directories
thinking they are unneeded and introduce weird errors when TestExpectations
still refer to nonexistent directories or files.

R=ojan@chromium.org
BUG=369385
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175748

[Dirk Pranke, 2014-05-05 21:15:40]

ping?

[ojan, 2014-05-07 02:00:12]

lgtm

[commit-bot: I haz the power, 2014-05-07 02:00:56]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/267803007/20001

[commit-bot: I haz the power, 2014-05-07 02:30:29]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  linux_blink_dbg on tryserver.blink
  linux_blink_rel on tryserver.blink
  mac_blink_rel on tryserver.blink
  win_blink_rel on tryserver.blink

[commit-bot: I haz the power, 2014-05-07 02:49:31]

FYI, CQ is re-trying this CL (attempt #2).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  linux_blink_dbg on tryserver.blink
  linux_blink_rel on tryserver.blink
  mac_blink_rel on tryserver.blink
  win_blink_rel on tryserver.blink

[commit-bot: I haz the power, 2014-05-07 03:03:10]

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

[commit-bot: I haz the power, 2014-05-07 03:03:10]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink

[Dirk Pranke, 2014-06-03 23:23:06]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-06-03 23:23:31]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/267803007/40001

[commit-bot: I haz the power, 2014-06-04 01:48:52]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/1...)
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10179)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/10500)

[commit-bot: I haz the power, 2014-06-04 01:58:49]

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

[commit-bot: I haz the power, 2014-06-04 01:58:49]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10182)

[Dirk Pranke, 2014-06-06 00:47:10]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-06-06 00:51:03]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/267803007/80001

[commit-bot: I haz the power, 2014-06-06 01:52:34]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10504)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/10894)

[commit-bot: I haz the power, 2014-06-06 02:08:23]

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

[commit-bot: I haz the power, 2014-06-06 02:08:23]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10518)

[Dirk Pranke, 2014-06-06 22:52:55]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-06-06 22:54:02]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/267803007/100001

[commit-bot: I haz the power, 2014-06-06 23:43:32]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/1...)
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10692)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/11091)

[commit-bot: I haz the power, 2014-06-06 23:52:03]

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

[commit-bot: I haz the power, 2014-06-06 23:52:04]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/10703)

[Dirk Pranke, 2014-06-07 16:42:03]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-06-07 16:43:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dpranke@chromium.org/267803007/100001

[commit-bot: I haz the power, 2014-06-07 17:45:35]

Change committed as 175748