feat: remove playbackRate blacklist for recent Android Chrome (#4321)

Android Chrome now supports playbackRate properly, so removes the blacklist added in #3246 for newer Chrome versions.
Adds `browser.CHROME_VERSION` as a necessary evil.
No longer blacklists for Chrome 58+ -- this could possibly be fixed since 52, but 58 is all I've been able to test on and most users should keep Chrome up to date.

src/js/tech/html5.js

@@ -761,7 +761,7 @@ Html5.canControlVolume = function() {
 Html5.canControlPlaybackRate = function() {
   // Playback rate API is implemented in Android Chrome, but doesn't do anything
   // https://github.com/videojs/video.js/issues/3180
-  if (browser.IS_ANDROID && browser.IS_CHROME) {
+  if (browser.IS_ANDROID && browser.IS_CHROME && browser.CHROME_VERSION < 58) {
     return false;
   }
   // IE will error if Windows Media Player not installed #3315

src/js/utils/browser.js

@@ -62,6 +62,14 @@ export const IS_NATIVE_ANDROID = IS_ANDROID && ANDROID_VERSION < 5 && appleWebki
 export const IS_FIREFOX = (/Firefox/i).test(USER_AGENT);
 export const IS_EDGE = (/Edge/i).test(USER_AGENT);
 export const IS_CHROME = !IS_EDGE && (/Chrome/i).test(USER_AGENT);
+export const CHROME_VERSION = (function() {
+  const match = USER_AGENT.match(/Chrome\/(\d+)/);
+
+  if (match && match[1]) {
+    return parseFloat(match[1]);
+  }
+  return null;
+}());
 export const IS_IE8 = (/MSIE\s8\.0/).test(USER_AGENT);
 export const IE_VERSION = (function() {
   const result = (/MSIE\s(\d+)\.\d/).exec(USER_AGENT);

test/unit/tech/html5.test.js

@@ -100,6 +100,32 @@ QUnit.test('test defaultPlaybackRate', function(assert) {
   assert.strictEqual(tech.defaultPlaybackRate(), 0.75, 'can be changed from the API');
 });
 
+QUnit.test('blacklist playbackRate support on older verisons of Chrome on Android', function(assert) {
+  if (!Html5.canControlPlaybackRate()) {
+    assert.ok(true, 'playbackRate is not supported');
+    return;
+  }
+
+  // Reset playbackrate - Firefox's rounding of playbackRate causes the rate not to change in canControlPlaybackRate() after a few instances
+  Html5.TEST_VID.playbackRate = 1;
+
+  const oldIsAndroid = browser.IS_ANDROID;
+  const oldIsChrome = browser.IS_CHROME;
+  const oldChromeVersion = browser.CHROME_VERSION;
+
+  browser.IS_ANDROID = true;
+  browser.IS_CHROME = true;
+  browser.CHROME_VERSION = 50;
+  assert.strictEqual(Html5.canControlPlaybackRate(), false, 'canControlPlaybackRate should return false on older Chrome');
+
+  browser.CHROME_VERSION = 58;
+  assert.strictEqual(Html5.canControlPlaybackRate(), true, 'canControlPlaybackRate should return true on newer Chrome');
+
+  browser.IS_ANDROID = oldIsAndroid;
+  browser.IS_CHROME = oldIsChrome;
+  browser.CHROME_VERSION = oldChromeVersion;
+});
+
 QUnit.test('test volume', function(assert) {
   if (!Html5.canControlVolume()) {
     assert.ok(true, 'Volume is not supported');