--- a/accessible/tests/mochitest/tree/test_media.html
+++ b/accessible/tests/mochitest/tree/test_media.html
@@ -40,16 +40,27 @@ https://bugzilla.mozilla.org/show_bug.cg
             role: ROLE_PROGRESSBAR,
             children: []
           },
           { // slider of progress bar
             role: ROLE_SLIDER,
             //name: "0:00 of 0:02 elapsed",
             children: []
           },
+          {
+            role: ROLE_TEXT_CONTAINER,
+            children: [
+              {
+                role: ROLE_TEXT_LEAF, // position text
+              },
+              {
+                role: ROLE_TEXT_LEAF, // duration text
+              }
+            ]
+          },
           { // mute button
             role: ROLE_PUSHBUTTON,
             name: "Mute",
             children: []
           },
           { // slider of volume bar
             role: ROLE_SLIDER,
             children: []

--- a/toolkit/content/tests/widgets/test_audiocontrols_dimensions.html
+++ b/toolkit/content/tests/widgets/test_audiocontrols_dimensions.html
@@ -12,17 +12,17 @@
 <div id="content">
   <audio id="audio" controls preload="auto"></audio>
 </div>
 
 <pre id="test">
 <script class="testbody" type="text/javascript">
   function loadedmetadata(event) {
     is(event.type, "loadedmetadata", "checking event type");
-    is(audio.clientHeight, 28, "checking height of audio element");
+    is(audio.clientHeight, 40, "checking height of audio element");
 
     SimpleTest.finish();
   }
 
   var audio = document.getElementById("audio");
 
   SpecialPowers.pushPrefEnv({"set": [["media.cache_size", 40000]]}, startTest);
   function startTest() {

--- a/toolkit/content/tests/widgets/test_videocontrols.html
+++ b/toolkit/content/tests/widgets/test_videocontrols.html
@@ -19,63 +19,68 @@
 /*
  * Positions of the  UI elements, relative to the upper-left corner of the
  * <video> box.
  */
 const videoWidth = 320;
 const videoHeight = 240;
 const videoDuration = 3.8329999446868896;
 
-const playButtonWidth = 28;
-const playButtonHeight = 28;
-const muteButtonWidth = 33;
-const muteButtonHeight = 28;
-const durationWidth = 34;
-const fullscreenButtonWidth = 28;
-const fullscreenButtonHeight = 28;
-const volumeSliderWidth = 32;
-const scrubberWidth = videoWidth - playButtonWidth - durationWidth - muteButtonWidth - volumeSliderWidth - fullscreenButtonWidth;
-const scrubberHeight = 28;
+const controlBarMargin = 9;
+
+const playButtonWidth = 30;
+const playButtonHeight = 40;
+const muteButtonWidth = 30;
+const muteButtonHeight = 40;
+const positionAndDurationWidth = 84;
+const fullscreenButtonWidth = 30;
+const fullscreenButtonHeight = 40;
+const volumeSliderWidth = 48;
+const volumeSliderMarginStart = 4;
+const volumeSliderMarginEnd = 6;
+const scrubberMargin = 9;
+const scrubberWidth = videoWidth - controlBarMargin - playButtonWidth - scrubberMargin * 2 - positionAndDurationWidth - muteButtonWidth - volumeSliderMarginStart - volumeSliderWidth - volumeSliderMarginEnd - fullscreenButtonWidth - controlBarMargin;
+const scrubberHeight = 40;
+
 
 // Play button is on the bottom-left
 const playButtonCenterX = 0 + Math.round(playButtonWidth / 2);
 const playButtonCenterY = videoHeight - Math.round(playButtonHeight / 2);
 // Mute button is on the bottom-right before the full screen button and volume slider
-const muteButtonCenterX = videoWidth - Math.round(muteButtonWidth / 2) - volumeSliderWidth - fullscreenButtonWidth;
+const muteButtonCenterX = videoWidth - Math.round(muteButtonWidth / 2) - volumeSliderWidth - fullscreenButtonWidth - controlBarMargin;
 const muteButtonCenterY = videoHeight - Math.round(muteButtonHeight / 2);
 // Fullscreen button is on the bottom-right at the far end
-const fullscreenButtonCenterX = videoWidth - Math.round(fullscreenButtonWidth / 2);
+const fullscreenButtonCenterX = videoWidth - Math.round(fullscreenButtonWidth / 2) - controlBarMargin;
 const fullscreenButtonCenterY = videoHeight - Math.round(fullscreenButtonHeight / 2);
 // Scrubber bar is between the play and mute buttons. We don't need it's
 // X center, just the offset of its box.
-const scrubberOffsetX = 0 + playButtonWidth;
+const scrubberOffsetX = controlBarMargin + playButtonWidth + scrubberMargin;
 const scrubberCenterY = videoHeight - Math.round(scrubberHeight / 2);
 
 var testnum = 1;
 var video = document.getElementById("video");
 
 const domUtil = SpecialPowers.Cc["@mozilla.org/inspector/dom-utils;1"]
                              .getService(SpecialPowers.Ci.inIDOMUtils);
 
 function getButtonByAttribute(aName, aValue) {
   var kids = domUtil.getChildrenForNode(video, true);
   var videocontrols = kids[1];
   return SpecialPowers.wrap(document)
     .getAnonymousElementByAttribute(videocontrols, aName, aValue);
 }
 
 function isMuteButtonMuted() {
-  var muteButton = getButtonByAttribute('class', 'muteButton');
+  var muteButton = getButtonByAttribute('anonid', 'muteButton');
   return muteButton.getAttribute('muted') === 'true';
 }
 
 function isVolumeSliderShowingCorrectVolume(expectedVolume) {
-  var volumeButton = getButtonByAttribute('anonid', 'volumeForeground');
-  let expectedPaddingRight = (1 - expectedVolume) * volumeSliderWidth + "px";
-  is(volumeButton.style.paddingRight, expectedPaddingRight,
+  var volumeControl = getButtonByAttribute('anonid', 'volumeControl');
+  is(+volumeControl.value, expectedVolume * 100,
      "volume slider should match expected volume");
 }
 
 function forceReframe() {
   // Setting display then getting the bounding rect to force a frame
   // reconstruction on the video element.
   video.style.display = "block";
   video.getBoundingClientRect();
@@ -224,17 +229,17 @@ function runTest(event) {
 
     /*
      * Click the slider at the 1/4 point with the mouse (jump backwards)
      */
     case 13:
       is(event.type, "seeked", "checking event type");
       ok(true, "video position is at " + video.currentTime);
       var expectedTime = videoDuration / 2;
-      ok(Math.abs(video.currentTime - expectedTime) < 0.1, "checking expected playback position");
+      ok(Math.abs(video.currentTime - expectedTime) < 0.25, "checking expected playback position");
 
       SimpleTest.executeSoon(() => {
         synthesizeMouse(video, scrubberOffsetX + (scrubberWidth / 4), scrubberCenterY, { });
       });
       break;
 
     case 14:
       is(event.type, "seeking", "checking event type");

--- a/toolkit/content/tests/widgets/test_videocontrols_standalone.html
+++ b/toolkit/content/tests/widgets/test_videocontrols_standalone.html
@@ -8,18 +8,19 @@
   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
 </head>
 <body>
 <p id="display"></p>
 
 <pre id="test">
 <script class="testbody" type="text/javascript">
 
-const videoWidth = 320;
-const videoHeight = 240;
+const videoBorderWidth = 1;
+const videoWidth = 320 + videoBorderWidth * 2;
+const videoHeight = 240 + videoBorderWidth * 2;
 
 function getMediaElement(aWindow) {
   return aWindow.document.getElementsByTagName("video")[0];
 }
 
 var popup = window.open("seek_with_sound.ogg");
 popup.addEventListener("load", function onLoad() {
   popup.removeEventListener("load", onLoad);
@@ -63,17 +64,17 @@ function runTestAudioPre() {
       })
     }
   })
 }
 
 function runTestAudio(aAudio) {
   info("User agent (help diagnose bug #943556): " + navigator.userAgent);
   var isAndroid = navigator.userAgent.includes("Android");
-  var expectedHeight = isAndroid ? 103 : 28;
+  var expectedHeight = isAndroid ? 103 : 42;
   var condition = function () {
     var boundingRect = aAudio.getBoundingClientRect();
     return boundingRect.height == expectedHeight;
   };
   waitForCondition(condition, function () {
     var boundingRect = aAudio.getBoundingClientRect();
     is(boundingRect.height, expectedHeight,
        "Height of audio element should be " + expectedHeight + ", which is equal to the controls bar.");

--- a/toolkit/content/tests/widgets/test_videocontrols_vtt.html
+++ b/toolkit/content/tests/widgets/test_videocontrols_vtt.html
@@ -15,17 +15,17 @@
 
 <pre id="test">
 <script clas="testbody" type="application/javascript">
   SimpleTest.waitForExplicitFinish();
 
   const domUtils = SpecialPowers.Cc["@mozilla.org/inspector/dom-utils;1"].
     getService(SpecialPowers.Ci.inIDOMUtils);
   const video = document.getElementById("video");
-  const ccBtn = getElementByAttribute("class", "closedCaptionButton");
+  const ccBtn = getElementByAttribute("anonid", "closedCaptionButton");
   const testCases = [];
 
   testCases.push(() => new Promise(resolve => {
     is(ccBtn.getAttribute("hidden"), "true", "CC button should hide");
 
     resolve();
   }));
 
@@ -41,18 +41,18 @@
     });
   }));
 
   testCases.push(() => new Promise(resolve => {
     const sub = video.addTextTrack("subtitles", "English", "en");
     sub.mode = "disabled";
 
     SimpleTest.executeSoon(() => {
-      is(ccBtn.getAttribute("hidden"), "", "CC button should show");
-      is(ccBtn.getAttribute("enabled"), "", "CC button should be disabled");
+      is(ccBtn.hasAttribute("hidden"), false, "CC button should show");
+      is(ccBtn.hasAttribute("enabled"), false, "CC button should be disabled");
 
       resolve();
     });
   }));
 
   testCases.push(() => new Promise(resolve => {
     const subtitle = video.addTextTrack("subtitles", "English", "en");
     subtitle.mode = "showing";

--- a/toolkit/content/widgets/videocontrols.xml
+++ b/toolkit/content/widgets/videocontrols.xml
@@ -237,19 +237,19 @@
                           <progress anonid="bufferBar" class="bufferBar" value="0" max="100"></progress>
                           <progress anonid="progressBar" class="progressBar" value="0" max="100"></progress>
                         </div>
                       </div>
                       <input type="range" anonid="scrubber" class="scrubber"/>
                     </div>
                     <span anonid="positionLabel" class="positionLabel" role="presentation"></span>
                     <span anonid="durationLabel" class="durationLabel" role="presentation"></span>
-                    <div anonid="positionDurationBox" class="positionDurationBox" role="none">
+                    <span anonid="positionDurationBox" class="positionDurationBox" aria-hidden="true">
                       &positionAndDuration.nameFormat;
-                    </div>
+                    </span>
                     <div anonid="controlBarSpacer" class="controlBarSpacer" hidden="true" role="none"></div>
                     <button anonid="muteButton"
                             class="muteButton"
                             mutelabel="&muteButton.muteLabel;"
                             unmutelabel="&muteButton.unmuteLabel;"/>
                     <div anonid="volumeStack" class="volumeStack progressContainer" role="none">
                       <input type="range" anonid="volumeControl" class="volumeControl" min="0" max="100" step="1"/>
                     </div>