Add output path command-line option to 'compile'.
Add output path command-line option to 'compile'.

BUG=409187
TEST=local
  - Ran 'compile.py' with this option inside the "simple chrome" workflow.
    
Add the ability to supply the name of the build output directory, rather than hard-code it to 'out'. This is needed to enable ChromeOS board output directories (e.g., 'out_x86-generic') for the simple chrome workflow.

Review URL: https://codereview.chromium.org/520143002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@291868 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build