src/vs/editor/contrib/codelens/browser/codelensWidget.ts/CodeLensViewZone/onComputedHeight
class CodeLensViewZone:	onComputedHeight(height: number): void {
		if (this._lastHeight === undefined) {
			this._lastHeight = height;
		} else if (this._lastHeight !== height) {
			this._lastHeight = height;
			this._onHeight();
		}
	}