SysInfoDisplayWayland: Make Display adhere to our coding style.

cpplint.py was recently updated in depot_tools, and introduces a newer
style check for the indentation of items in a class declaration.
Merge pull request #300 from rakuco/SIDW-style-fix

SysInfoDisplayWayland: Make Display adhere to our coding style.
Bump version to 0.55
[Content] TCT crash and passrate fixes

Implement scanFile method which is heavily used by the TCT web api test suite.

Fix a crash for filter with invalid parameters (no bug yet).

Rename uri to path conversion methods more aligned with chromium.

Add test code for scanFile