This adds an interface for DocumentsService
so that we can mock it.   It also adds a mock class
that can be used in testing.

Added a test for CreateDirectory and GetFile on the GDataFilesystem class.

BUG=chromium-os:27338
TEST=ran new unit tests
Review URL: https://chromiumcodereview.appspot.com/9582037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@125870 0039d316-1c4b-4281-b951-d872f2087c98
5 files changed