src/vs/editor/common/viewModel/overviewZoneManager.ts/OverviewZoneManager/setOuterHeight
class OverviewZoneManager:	public setOuterHeight(outerHeight: number): boolean {
		if (this._outerHeight === outerHeight) {
			return false;
		}
		this._outerHeight = outerHeight;
		this._colorZonesInvalid = true;
		return true;
	}