Alphabetize and dedup .gypi in bindings/, core/, and modules/

A clean-up: noticed some duplicates, fixed in this CL.

TBR=abarth, haraken

Review URL: https://codereview.chromium.org/227483002

git-svn-id: svn://svn.chromium.org/blink/trunk@170956 bbb929c8-8fbe-4397-9dbb-9b2b20218538