Fixed the resolution doesn't match LCD resolution when using
Systeminfo DISPLAY attribute.

BUG=XWALK-1927
Merge pull request #338 from qjia7/master

Fixed the resolution doesn't match LCD resolution when using Systeminfo DISPLAY attribute.
[Filesystem] Fix and complete the API

Implement the spec.
Fix and pass the TCT tests.
Fix and complete the example.

BUG=XWALK-1071
BUG=XWALK-1827