RELNOTES[NEW]: Add goog.dom.getCanvasContext2D.
RELNOTES[NEW]: Add goog.dom.getCanvasContext2D.

canvas.getContext returns {Object} in externs/html5.js because it might return different types based on the argument. This simple helper provides the correct type information.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=129636537

redforks/closure-library,redforks/closure-library,redforks/closure-library,redforks/closure-library