Use common H.264 check in tests

Avoid duplicating this logic in multiple places.

tests/test.h264.js

@@ -4,6 +4,7 @@ import Display from '../core/display.js';
 import { H264Parser } from '../core/decoders/h264.js';
 import H264Decoder from '../core/decoders/h264.js';
 import Base64 from '../core/base64.js';
+import { supportsWebCodecsH264Decode } from '../core/util/browser.js';
 
 import FakeWebSocket from './fake.websocket.js';
 
@@ -29,32 +30,6 @@ const redGreenBlue16x16Video = new Uint8Array(Base64.decode(
     '4AA5DRJMnkycJk4TPwAAAAFBiIga8RigADVVHAAGaGOAANtuAAAAAUGIkBr///wRRQABVf8c' +
     'AAcho4AAiD4='));
 
-let _haveH264Decode = null;
-
-async function haveH264Decode() {
-    if (_haveH264Decode !== null) {
-        return _haveH264Decode;
-    }
-
-    if (!('VideoDecoder' in window)) {
-        _haveH264Decode = false;
-        return false;
-    }
-
-    // We'll need to make do with some placeholders here
-    const config = {
-        codec: 'avc1.42401f',
-        codedWidth: 1920,
-        codedHeight: 1080,
-        optimizeForLatency: true,
-    };
-
-    let support = await VideoDecoder.isConfigSupported(config);
-    _haveH264Decode = support.supported;
-
-    return _haveH264Decode;
-}
-
 function createSolidColorFrameBuffer(color, width, height) {
     const r = (color >> 24) & 0xff;
     const g = (color >> 16) & 0xff;
@@ -158,8 +133,8 @@ describe('H.264 Parser', function () {
 describe('H.264 Decoder Unit Test', function () {
     let decoder;
 
-    beforeEach(async function () {
-        if (!await haveH264Decode()) {
+    beforeEach(function () {
+        if (!supportsWebCodecsH264Decode) {
             this.skip();
             return;
         }
@@ -213,8 +188,8 @@ describe('H.264 Decoder Functional Test', function () {
     before(FakeWebSocket.replace);
     after(FakeWebSocket.restore);
 
-    beforeEach(async function () {
-        if (!await haveH264Decode()) {
+    beforeEach(function () {
+        if (!supportsWebCodecsH264Decode) {
             this.skip();
             return;
         }