diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-into-pointer.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-into-pointer.html
new file mode 100644
index 00000000000000..46d3f2eaa88638
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-into-pointer.html
@@ -0,0 +1,42 @@
+<!doctype html>
+<title>pointer updates (moveBefore non-source nodes into the pointer)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"><br id="br-node"><span id="text-holder">x</span></div>
+<script>
+var brEvents = [];
+var textEvents = [];
+var a1 = 0;
+var b1 = 0;
+var c1 = 0;
+var a2 = 0;
+var b2 = 0;
+var c2 = 0;
+</script>
+<video id="v-br"><source id="br-a" onerror="a1++; brEvents.push('a')"><source id="br-b" onerror="b1++; brEvents.push('b')" src="resources/delayed-broken-video.py?br"><source id="br-c" onerror="c1++; brEvents.push('c')"></video>
+<video id="v-text"><source id="text-a" onerror="a2++; textEvents.push('a')"><source id="text-b" onerror="b2++; textEvents.push('b')" src="resources/delayed-broken-video.py?text"><source id="text-c" onerror="c2++; textEvents.push('c')"></video>
+<script>
+async_test(function(t) {
+  var videoBr = document.getElementById('v-br');
+  var videoText = document.getElementById('v-text');
+  assert_implements(typeof videoBr.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+  assert_implements(typeof videoText.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  videoBr.moveBefore(document.getElementById('br-node'), document.getElementById('br-c'));
+  videoText.moveBefore(document.getElementById('text-holder').firstChild, document.getElementById('text-c'));
+
+  window.onload = t.step_func(function() {
+    assert_equals(a1, 1, 'error events on br test a');
+    assert_equals(b1, 1, 'error events on br test b');
+    assert_equals(c1, 1, 'error events on br test c');
+    assert_array_equals(brEvents, ['a', 'b', 'c'], 'br test processed source order');
+
+    assert_equals(a2, 1, 'error events on text test a');
+    assert_equals(b2, 1, 'error events on text test b');
+    assert_equals(c2, 1, 'error events on text test c');
+    assert_array_equals(textEvents, ['a', 'b', 'c'], 'text test processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-pointer-after-out.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-pointer-after-out.html
new file mode 100644
index 00000000000000..cb7c664aecf448
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-non-source-pointer-after-out.html
@@ -0,0 +1,39 @@
+<!doctype html>
+<title>pointer updates (moveBefore non-source pointerAfter out of the media element)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py">x<source id="source-c" onerror="c++; events.push('c')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  var text = null;
+  for (var i = 0; i < video.childNodes.length; ++i) {
+    if (video.childNodes[i].nodeType == Node.TEXT_NODE && video.childNodes[i].data == 'x') {
+      text = video.childNodes[i];
+      break;
+    }
+  }
+  assert_not_equals(text, null, 'text node pointerAfter exists');
+
+  // Move the text node that is pointerAfter out while b is pending.
+  document.getElementById('holder').moveBefore(text, null);
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(c, 1, 'error events on c');
+    assert_array_equals(events, ['a', 'b', 'c'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-before-pointer.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-before-pointer.html
new file mode 100644
index 00000000000000..7439a5d07fb887
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-before-pointer.html
@@ -0,0 +1,36 @@
+<!doctype html>
+<title>pointer updates (moveBefore pointerAfter before the pointer)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"><source id="source-d"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+var d = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"><source id="source-c" onerror="c++; events.push('c')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  // Move pointerAfter to before pointerBefore: a, b | c becomes a, c, b |.
+  video.moveBefore(document.getElementById('source-c'), document.getElementById('source-b'));
+
+  var sourceD = document.getElementById('source-d');
+  sourceD.onerror = function() { d++; events.push('d'); };
+  video.moveBefore(sourceD, null);
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(c, 0, 'error events on c');
+    assert_equals(d, 1, 'error events on d');
+    assert_array_equals(events, ['a', 'b', 'd'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-out.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-out.html
new file mode 100644
index 00000000000000..896f5feb01c8b0
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-after-out.html
@@ -0,0 +1,32 @@
+<!doctype html>
+<title>pointer updates (moveBefore pointerAfter out of the media element)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+var d = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"><source id="source-c" onerror="c++; events.push('c')"><source id="source-d" onerror="d++; events.push('d')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  // Move pointerAfter out while b is pending. d should become the next candidate.
+  document.getElementById('holder').moveBefore(document.getElementById('source-c'), null);
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(c, 0, 'error events on c');
+    assert_equals(d, 1, 'error events on d');
+    assert_array_equals(events, ['a', 'b', 'd'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-out.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-out.html
new file mode 100644
index 00000000000000..a17d0fba5fc97b
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-out.html
@@ -0,0 +1,30 @@
+<!doctype html>
+<title>pointer updates (moveBefore pointerBefore out of the media element)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"><source id="source-c" onerror="c++; events.push('c')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  // Move the current candidate, which is pointerBefore, out while it is pending.
+  document.getElementById('holder').moveBefore(document.getElementById('source-b'), null);
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(c, 1, 'error events on c');
+    assert_array_equals(events, ['a', 'b', 'c'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-within.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-within.html
new file mode 100644
index 00000000000000..1caa8f4ec80ac9
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-pointer-before-within.html
@@ -0,0 +1,46 @@
+<!doctype html>
+<title>pointer updates (moveBefore pointerBefore within the media element)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"><source id="source-s3"></div>
+<script>
+var events = [];
+var s1 = 0;
+var s2 = 0;
+var s3 = 0;
+var moved = false;
+
+function s2_error() {
+  s2++;
+  events.push('s2');
+  if (moved) {
+    return;
+  }
+  moved = true;
+  var video = document.getElementById('v');
+  var source1 = document.getElementById('source-s1');
+  var source2 = document.getElementById('source-s2');
+  var source3 = document.getElementById('source-s3');
+  source1.src = 'resources/delayed-broken-video.py?should-not-be-reprocessed';
+  source3.onerror = function() { s3++; events.push('s3'); };
+
+  // Move pointerBefore before s1. The pointer should remain after s1.
+  video.moveBefore(source2, source1);
+  video.moveBefore(source3, null);
+}
+</script>
+<video id="v"><source id="source-s1" onerror="s1++; events.push('s1')"><source id="source-s2" onerror="s2_error()" src="resources/delayed-broken-video.py"></video>
+<script>
+async_test(function(t) {
+  assert_implements(typeof document.getElementById('v').moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  window.onload = t.step_func(function() {
+    assert_equals(s1, 1, 'error events on s1');
+    assert_equals(s2, 1, 'error events on s2');
+    assert_equals(s3, 1, 'error events on s3');
+    assert_array_equals(events, ['s1', 's2', 's3'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-processed-source-to-end.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-processed-source-to-end.html
new file mode 100644
index 00000000000000..94be159e112e57
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-processed-source-to-end.html
@@ -0,0 +1,37 @@
+<!doctype html>
+<title>pointer updates (moveBefore processed source to the end)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var events = [];
+var s1 = 0;
+var s2 = 0;
+var moved = false;
+
+function s2_error() {
+  s2++;
+  events.push('s2');
+  if (moved) {
+    return;
+  }
+  moved = true;
+  var video = document.getElementById('v');
+  var source1 = document.getElementById('source-s1');
+  source1.src = 'resources/delayed-broken-video.py?move-processed-source-to-end';
+  video.moveBefore(source1, null);
+}
+</script>
+<video id="v"><source id="source-s1" onerror="s1++; events.push('s1')"><source id="source-s2" onerror="s2_error()" src="resources/delayed-broken-video.py"></video>
+<script>
+async_test(function(t) {
+  assert_implements(typeof document.getElementById('v').moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  window.onload = t.step_func(function() {
+    assert_equals(s1, 2, 'error events on s1');
+    assert_equals(s2, 1, 'error events on s2');
+    assert_array_equals(events, ['s1', 's2', 's1'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-empty-video.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-empty-video.html
new file mode 100644
index 00000000000000..d37f5a077ad633
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-empty-video.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<title>pointer updates (moveBefore source into an empty media element)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"><source id="source-x"></div>
+<script>
+var events = [];
+var b = 0;
+var x = 0;
+</script>
+<video id="v"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  var holder = document.getElementById('holder');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  var sourceX = document.getElementById('source-x');
+  sourceX.onerror = function() { x++; events.push('x'); };
+
+  // Move the current candidate out so the video has no children while b is pending.
+  holder.moveBefore(document.getElementById('source-b'), null);
+
+  // Move an existing source from another parent into the empty video.
+  video.moveBefore(sourceX, null);
+
+  window.onload = t.step_func(function() {
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(x, 1, 'error events on x');
+    assert_array_equals(events, ['b', 'x'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-pointer.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-pointer.html
new file mode 100644
index 00000000000000..d3a111687d1d7d
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-into-pointer.html
@@ -0,0 +1,35 @@
+<!doctype html>
+<title>pointer updates (moveBefore source into the pointer)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<div id="holder"><source id="source-x"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+var x = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"><source id="source-c" onerror="c++; events.push('c')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  var sourceX = document.getElementById('source-x');
+  sourceX.onerror = function() { x++; events.push('x'); };
+
+  // Move an existing source from another parent to the pointer position: b | c.
+  video.moveBefore(sourceX, document.getElementById('source-c'));
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(x, 1, 'error events on x');
+    assert_equals(c, 1, 'error events on c');
+    assert_array_equals(events, ['a', 'b', 'x', 'c'], 'processed source order');
+    t.done();
+  });
+});
+</script>
diff --git a/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-within-pointer.html b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-within-pointer.html
new file mode 100644
index 00000000000000..5bf2273444ae0a
--- /dev/null
+++ b/html/semantics/embedded-content/media-elements/loading-the-media-resource/resource-selection-pointer-move-source-within-pointer.html
@@ -0,0 +1,33 @@
+<!doctype html>
+<title>pointer updates (moveBefore source within the pointer)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var events = [];
+var a = 0;
+var b = 0;
+var c = 0;
+var x = 0;
+var d = 0;
+</script>
+<video id="v"><source id="source-a" onerror="a++; events.push('a')"><source id="source-b" onerror="b++; events.push('b')" src="resources/delayed-broken-video.py"><source id="source-c" onerror="c++; events.push('c')"><source id="source-x" onerror="x++; events.push('x')"><source id="source-d" onerror="d++; events.push('d')"></video>
+<script>
+async_test(function(t) {
+  var video = document.getElementById('v');
+  assert_implements(typeof video.moveBefore == 'function', 'ParentNode.moveBefore() is required for this test');
+
+  // Move a later source to the pointer position: b | c.
+  video.moveBefore(document.getElementById('source-x'), document.getElementById('source-c'));
+
+  window.onload = t.step_func(function() {
+    assert_equals(a, 1, 'error events on a');
+    assert_equals(b, 1, 'error events on b');
+    assert_equals(x, 1, 'error events on x');
+    assert_equals(c, 1, 'error events on c');
+    assert_equals(d, 1, 'error events on d');
+    assert_array_equals(events, ['a', 'b', 'x', 'c', 'd'], 'processed source order');
+    t.done();
+  });
+});
+</script>
