Revert 270872 "Move all callers of GetHomeDir() to PathService::..."

Revert 270872 "Move all callers of GetHomeDir() to PathService::..."

> Move all callers of GetHomeDir() to PathService::Get(base::DIR_HOME).
> 
> * Fixes GetHomeDir() for multi-profiles case on Chrome OS.
> * Once user signs in on Chrome OS base::DIR_HOME is overridden with primary user homedir.
> * Added content switch --homedir to pass that information to ppapi plugins since they run in a separate process and previous base::DIR_HOME override does not apply there.
> 
> This fix doesn't require checking for --multi-profiles switch
> since user_id hash is known even without it.
> 
> BUG=331530
> TBR=vitalybuka@chromium.org
> 
> Review URL: https://codereview.chromium.org/200473002

This test has caused two tests to start failing on the chromeos valgrind bots:
http://build.chromium.org/p/chromium.memory.fyi/builders/Chromium%20OS%20%28valgrind%29%286%29/builds/25884
http://build.chromium.org/p/chromium.memory.fyi/builders/Chromium%20OS%20%28valgrind%29%285%29/builds/26990

TBR=nkostylev@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270951

[benwells, 2014-05-16 06:33:05]

Committed patchset #1 manually as r270951.