src/vs/editor/browser/view.ts/View/getOffsetForColumn
class View:	public getOffsetForColumn(modelLineNumber: number, modelColumn: number): number {
		const modelPosition = this._context.viewModel.model.validatePosition({
			lineNumber: modelLineNumber,
			column: modelColumn
		});
		const viewPosition = this._context.viewModel.coordinatesConverter.convertModelPositionToViewPosition(modelPosition);
		this._flushAccumulatedAndRenderNow();
		const visibleRange = this._viewLines.visibleRangeForPosition(new Position(viewPosition.lineNumber, viewPosition.column));
		if (!visibleRange) {
			return -1;
		}
		return visibleRange.left;
	}