tree 4e47968ec91db48de87200d0bfe383cf1a9a6167
parent 6de8a0e51f0cf8c52a4de672d4b2d8f2d78d143e
author Daichi Hirono <hirono@google.com> 1445845194 +0900
committer Daichi Hirono <hirono@google.com> 1446609500 +0900

Extends MtpDatabase so that it can handle child documents.

The CL extracts common routines for root documents and child documents,
adds new methods for child documents, and let the common routines from
the new methods.

BUG=25162822

Change-Id: Ie6f0092e584ae12c89d43593701debeb76f6f3cb