[Android] Native File System API
Completed features list:

Create file
Read file
Write file
Remove file
Create Directory
List Directory Entries
Remove Directory

BUG=https://crosswalk-project.org/jira/browse/XWALK-672
Merge pull request #2048 from shawngao5/native_file_system_android

[Android] Native File System API
DEPS.xwalk: Roll chromium-crosswalk (c282374 -> 63ea355).

63ea355 Merge pull request #163 from halton/update_deps_git
1dfe443 Merge pull request #164 from hmin/init-readback-handler
d352a08 [TEMP] Publish DEPS for Chromium 36.0.1985.18
5fba371 [Android] Add code path for initializing ContentReadbackHandler
881367b Merge pull request #160 from tmpsantos/glib_mainloop
1687714 [Extensions] Build glib message pump on Ozone
Use .DEPS.git instead of DEPS

This commit is allow developers get GIT version of dependencies.

Most of dependencies in <release_dir>/DEPS are pointing to subversion.
Unfortunately, svn command behind firewall randomly fails with error
"501 Not Implemented". Instead, git repos are more stable to fetch.

Since upstream is switching SVN to GIT, it is time to switch to
GIT(.DEPS.git) totally.

BUG=XWALK-1894