Add extern for CanvasRenderingContext2d.letterspacing.
@@ -422,6 +422,9 @@ CanvasDrawingStyles.prototype.textAlign;
/** @type {string} */
CanvasDrawingStyles.prototype.textBaseline;
+/** @type {string} */
+CanvasDrawingStyles.prototype.letterSpacing;
+
// TODO(dramaix): replace this with @record.
/**
* @constructor
@@ -894,6 +897,9 @@ BaseRenderingContext2D.prototype.textAlign;
/** @type {string} */
BaseRenderingContext2D.prototype.textBaseline;
+/** @type {string} */
+BaseRenderingContext2D.prototype.letterSpacing;
+
/** @type {number} */
BaseRenderingContext2D.prototype.lineDashOffset;
