src/vs/editor/common/viewModel/viewModelImpl.ts/ViewModel/getAllOverviewRulerDecorations
class ViewModel:	public getAllOverviewRulerDecorations(theme: EditorTheme): OverviewRulerDecorationsGroup[] {
		const decorations = this.model.getOverviewRulerDecorations(this._editorId, filterValidationDecorations(this._configuration.options));
		const result = new OverviewRulerDecorations();
		for (const decoration of decorations) {
			const decorationOptions = <ModelDecorationOptions>decoration.options;
			const opts = decorationOptions.overviewRuler;
			if (!opts) {
				continue;
			}
			const lane = <number>opts.position;
			if (lane === 0) {
				continue;
			}
			const color = opts.getColor(theme.value);
			const viewStartLineNumber = this.coordinatesConverter.getViewLineNumberOfModelPosition(decoration.range.startLineNumber, decoration.range.startColumn);
			const viewEndLineNumber = this.coordinatesConverter.getViewLineNumberOfModelPosition(decoration.range.endLineNumber, decoration.range.endColumn);

			result.accept(color, decorationOptions.zIndex, viewStartLineNumber, viewEndLineNumber, lane);
		}
		return result.asArray;
	}