Pause refresh when page is hidden (#177693)

## Summary

close https://github.com/elastic/kibana/issues/1878

Pauses auto-refresh when a page is not visible. 
I tested and didn't notice any issues, but looking for more testing help


## Release Notes

Auto-refresh pauses when the page is not visible.

src/plugins/data/public/query/timefilter/lib/auto_refresh_loop.test.ts

@@ -203,3 +203,39 @@ test('calling older done() is ignored', () => {
   jest.advanceTimersByTime(501);
   expect(fn1).toHaveBeenCalledTimes(2);
 });
+
+test('pauses if page is not visible', () => {
+  let mockPageVisibility: DocumentVisibilityState = 'visible';
+  jest.spyOn(document, 'visibilityState', 'get').mockImplementation(() => mockPageVisibility);
+
+  const { loop$, start, stop } = createAutoRefreshLoop();
+
+  const fn = jest.fn((done) => done());
+  loop$.subscribe(fn);
+
+  jest.advanceTimersByTime(5000);
+  expect(fn).not.toBeCalled();
+
+  start(1000);
+
+  jest.advanceTimersByTime(1001);
+  expect(fn).toHaveBeenCalledTimes(1);
+
+  mockPageVisibility = 'hidden';
+  document.dispatchEvent(new Event('visibilitychange'));
+
+  jest.advanceTimersByTime(1001);
+  expect(fn).toHaveBeenCalledTimes(1);
+
+  mockPageVisibility = 'visible';
+  document.dispatchEvent(new Event('visibilitychange'));
+  expect(fn).toHaveBeenCalledTimes(2);
+
+  jest.advanceTimersByTime(1001);
+  expect(fn).toHaveBeenCalledTimes(3);
+
+  stop();
+
+  jest.advanceTimersByTime(5000);
+  expect(fn).toHaveBeenCalledTimes(3);
+});

src/plugins/data/public/query/timefilter/lib/auto_refresh_loop.ts

@@ -7,8 +7,9 @@
  */
 
 import { defer, Subject } from 'rxjs';
-import { finalize, map } from 'rxjs/operators';
+import { finalize, map, delayWhen, filter } from 'rxjs/operators';
 import { once } from 'lodash';
+import { createPageVisibility$ } from './page_visibility';
 
 export type AutoRefreshDoneFn = () => void;
 
@@ -18,6 +19,8 @@ export type AutoRefreshDoneFn = () => void;
  * When auto refresh loop emits, it won't continue automatically,
  * until each subscriber calls received `done` function.
  *
+ * Also, it will pause when the page is not visible.
+ *
  * @internal
  */
 export const createAutoRefreshLoop = () => {
@@ -51,6 +54,12 @@ export const createAutoRefreshLoop = () => {
     _timeoutHandle = -1;
   }
 
+  const pageVisible$ = createPageVisibility$().pipe(
+    filter((visibility) => visibility === 'visible')
+  );
+
+  const tickWhenVisible$ = tick.pipe(delayWhen(() => pageVisible$));
+
   return {
     stop: () => {
       _timeout = 0;
@@ -65,7 +74,7 @@ export const createAutoRefreshLoop = () => {
     loop$: defer(() => {
       subscribersCount++;
       start(); // restart the loop on a new subscriber
-      return tick.pipe(map((doneCb) => once(doneCb))); // each subscriber allowed to call done only once
+      return tickWhenVisible$.pipe(map((doneCb) => once(doneCb))); // each subscriber allowed to call done only once
     }).pipe(
       finalize(() => {
         subscribersCount--;

src/plugins/data/public/query/timefilter/lib/page_visibility.test.ts

@@ -0,0 +1,28 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { createPageVisibility$ } from './page_visibility';
+
+let mockPageVisibility: DocumentVisibilityState = 'visible';
+jest.spyOn(document, 'visibilityState', 'get').mockImplementation(() => mockPageVisibility);
+
+test('createPageVisibility$ returns an observable that emits visibility state', () => {
+  const pageVisibility$ = createPageVisibility$();
+
+  const fn = jest.fn();
+  pageVisibility$.subscribe(fn);
+
+  expect(fn).toHaveBeenCalledTimes(1);
+  expect(fn).toHaveBeenLastCalledWith('visible');
+
+  mockPageVisibility = 'hidden';
+  document.dispatchEvent(new Event('visibilitychange'));
+
+  expect(fn).toHaveBeenCalledTimes(2);
+  expect(fn).toHaveBeenLastCalledWith('hidden');
+});

src/plugins/data/public/query/timefilter/lib/page_visibility.ts

@@ -0,0 +1,18 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { fromEvent, Observable } from 'rxjs';
+import { map, shareReplay, startWith } from 'rxjs/operators';
+
+export function createPageVisibility$(): Observable<DocumentVisibilityState> {
+  return fromEvent(document, 'visibilitychange').pipe(
+    startWith(document.visibilityState),
+    map(() => document.visibilityState),
+    shareReplay({ refCount: true, bufferSize: 1 })
+  );
+}