[Tizen] Fix: The screen displayed abnormally when playing some size of html5 mp4 videos on Tizen IVI.

Bug report: https://crosswalk-project.org/jira/browse/XWALK-1781
Questions:
1. Does the situation that a clip not RGBA happend a lot?
2. What other video player normal do for this kind of clip? realign as this PR? or report a corrupted? Or continue play with the bad image.
3. Does this way is correct to identify the video clip that not RGBA aligned?