Revert of Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating...

Revert of Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating new (https://codereview.chromium.org/197233008/)

Reason for revert:
Best guess that this broke
SyncFileSystemApiTest.WriteFileThenGetUsage
on XP Tests(1).

http://build.chromium.org/p/chromium.win/builders/XP%20Tests%20%281%29/builds/30601/steps/browser_tests/logs/WriteFileThenGetUsage

If not, we can just re-revert or reland it after a few cycles.

Original issue's description:
> Add a parameter to FileStreamWriter::CreateForLocalFile to allow creating new files as well as writing to existing files.
> See https://codereview.chromium.org/18023022/ for context; this is needed by upcoming IDB Blob support.
>
> Tzik, please do primary review for filesystem; Kinaba, please review as ChromeOS owner.
>
> BUG=108012
> R=kinaba,tzik
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=258120

TBR=kinaba@chromium.org,tzik@chromium.org,ericu@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=108012

Review URL: https://codereview.chromium.org/206073006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258256 0039d316-1c4b-4281-b951-d872f2087c98