add a LinuxSandbox::HasOpenDirectories() sanity check

BUG=269806

Review URL: https://codereview.chromium.org/24055003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233100 0039d316-1c4b-4281-b951-d872f2087c98
Add alaw codec for .wav files.

Also add corresponding test. (The test media is already there.)

BUG=chromium:217772
TEST=Played 2 test files on Pixel.

Review URL: https://codereview.chromium.org/25660014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233101 0039d316-1c4b-4281-b951-d872f2087c98
Fix parsing of vmstat, improve meminfo parsing, and add unittests

The parsing of both vmstat and meminfo was previously based on fixed
positions for various entries with the files, and meminfo already had
some iteration code for where this assumption wasn't working.
Neither of those files make guarantees about positions or even
existence of some of the entries.  This fixes the issue entirely by
iterating through the files for all entries, and adds unit tests to
make sure they work properly with files from different kernels.

This does change the behavior of the meminfo parsing code a bit to
make it more permissive than previously, but that should also ensure
that it works better on older or different kernels.

BUG=295111,309930
TEST=base_unittests  --gtest_filter=SystemMetricsTest.*
R=brettw@chromium.org

Review URL: https://codereview.chromium.org/34683007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233102 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233101
SVN changes up to revision 233102