Add platform_utils and stub test lists for Linux.

Add platform_utils and stub test lists for Linux.

This allows the LayoutTest harness to run on Linux. Note that the tests still
don't run properly because Linux test_shell is missing the ability to read URLs
from stdin (causing the test_shell to just sit there waiting for input). I'll
add that in another CL.

BUG=4281

[pink (ping after 24hrs), 2008-11-13 18:24:45]

LGTM, though I'm no python expert.

[tony, 2008-11-13 18:46:39]

LGTM

In the long run, it would probably be nice if we could have a single
tests_fixable.txt for all platforms with annotations for each platform.  This
will probably have to wait until after Pam finishes moving the test results
around.

[Elliot Glaysher, 2008-11-14 01:06:17]

After Pam's recent changes to how everything works, you're going to have to add
something like:

  def PlatformDir(self):
    """Returns the most specific directory name where platform specific
    results live.
    """
    return 'chromium-linux'

to platform_utils_linux.py.

[Pam (message me for reviews), 2008-11-14 01:17:02]

On 2008/11/13 18:46:39, tony wrote:
> LGTM
> 
> In the long run, it would probably be nice if we could have a single
> tests_fixable.txt for all platforms with annotations for each platform.  This
> will probably have to wait until after Pam finishes moving the test results
> around.

I'm done moving tests.

Last time we discussed it, we decided it was easiest to have separate files for
each platform.  I don't remember exactly who was in on that discussion, though,
and I have no objection to re-opening it (maybe in a thread on chromium-dev).

- Pam

[Michael Moss, 2008-11-17 18:37:46]

>   def PlatformDir(self):

Done.

[tony, 2008-11-17 19:20:14]

LG