Split gdata_file_system_interface.h from gdata_file_system.h
Now mock_gdata_file_system includes gdata_file_system_interface.h.
This is for preparing another filesystem using the file system interface.
gdata_file_system_interface.h is extracted from gdata_file_system.h, and removed the following unused callback typedefs:
- GetJsonDocumentCallback
- GetDocumentResourceIdCallback
BUG=chromium:127728
TEST=compile, all tests run
Review URL: https://chromiumcodereview.appspot.com/
10696190
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146302 0039d316-1c4b-4281-b951-d872f2087c98