src/vs/workbench/contrib/output/browser/outputView.ts/OutputViewPane/onDidChangeVisibility
class OutputViewPane:	private onDidChangeVisibility(visible: boolean): void {
		this.editor.setVisible(visible);
		let channel: IOutputChannel | undefined = undefined;
		if (visible) {
			channel = this.channelId ? this.outputService.getChannel(this.channelId) : this.outputService.getActiveChannel();
		}
		if (channel) {
			this.setInput(channel);
		} else {
			this.clearInput();
		}
	}