Fix deps problems in Jinja template use in build/scripts

Three targets are missing correct Jinja template dependencies:
* MediaFeatureNames
* MediaFeatures
* MediaTypeNames
This fixes them, so they rebuild properly.

Also minor style/order fixes.

R=abarth

Review URL: https://codereview.chromium.org/235673007

git-svn-id: svn://svn.chromium.org/blink/trunk@171421 bbb929c8-8fbe-4397-9dbb-9b2b20218538