--- a/testing/web-platform/tests/media-source/mediasource-duration.html
+++ b/testing/web-platform/tests/media-source/mediasource-duration.html
@@ -23,19 +23,16 @@
 
                   // Append all the segments
                   test.expectEvent(sourceBuffer, 'updateend', 'sourceBuffer');
                   test.expectEvent(mediaElement, 'playing', 'Playing triggered');
                   sourceBuffer.appendBuffer(mediaData);
 
                   test.waitForExpectedEvents(function()
                   {
-                      assert_equals(mediaElement.duration, fullDuration, 'mediaElement fullDuration');
-                      assert_equals(mediaSource.duration, fullDuration, 'mediaSource fullDuration');
-
                       test.expectEvent(mediaElement, 'seeking', 'seeking to seekTo');
                       test.expectEvent(mediaElement, 'timeupdate', 'timeupdate while seeking to seekTo');
                       test.expectEvent(mediaElement, 'seeked', 'seeked to seekTo');
                       mediaElement.currentTime = seekTo;
                       assert_true(mediaElement.seeking, 'mediaElement.seeking (to seekTo)');
                   });
 
                   test.waitForExpectedEvents(function()
@@ -50,19 +47,19 @@
                       assert_true(sourceBuffer.updating, 'sourceBuffer.updating');
                       test.expectEvent(sourceBuffer, 'updatestart', 'sourceBuffer');
                       test.expectEvent(sourceBuffer, 'update', 'sourceBuffer');
                       test.expectEvent(sourceBuffer, 'updateend', 'sourceBuffer');
                   });
 
                   test.waitForExpectedEvents(function()
                   {
+                      // remove will not remove partial frames. The truncated duration is as such the highest end time.
+                      truncatedDuration = sourceBuffer.buffered.end(sourceBuffer.buffered.length-1);
                       assert_greater_than_equal(mediaElement.currentTime, seekTo, 'Playback time has reached seekTo');
-                      assert_equals(mediaElement.duration, fullDuration, 'mediaElement fullDuration after seekTo');
-                      assert_equals(mediaSource.duration, fullDuration, 'mediaSource fullDuration after seekTo');
                       test.expectEvent(mediaElement, 'seeking', 'Seeking to truncated duration');
 
                       assert_false(sourceBuffer.updating, 'sourceBuffer.updating');
 
                       mediaSource.duration = truncatedDuration;
 
                       assert_true(mediaElement.seeking, 'Seeking after setting truncatedDuration');
                   });
@@ -130,18 +127,20 @@
               test.expectEvent(mediaElement, 'timeupdate', 'timeupdate while finishing seek to truncatedDuration');
               test.expectEvent(mediaElement, 'seeked', 'seeked to truncatedDuration');
 
               // Call endOfStream() to complete the pending seek.
               mediaSource.endOfStream();
 
               test.waitForExpectedEvents(function()
               {
-                  assert_equals(mediaElement.currentTime, truncatedDuration,
+                  assert_greater_than_equal(mediaElement.currentTime, truncatedDuration,
                                 'Playback time has reached truncatedDuration');
+                  // The mediaSource.readyState is "ended". Buffered ranges have been adjusted to the longest track.
+                  truncatedDuration = sourceBuffer.buffered.end(sourceBuffer.buffered.length-1);
                   assert_equals(mediaElement.duration, truncatedDuration,
                                 'mediaElement truncatedDuration after seek to it');
                   assert_equals(mediaSource.duration, truncatedDuration,
                                 'mediaSource truncatedDuration after seek to it');
                   assert_false(mediaElement.seeking, 'mediaElement.seeking after seeked to truncatedDuration');
 
                   test.done();
               });
@@ -153,63 +152,54 @@
 
               var fullDuration = segmentInfo.duration;
               var newDuration = 0.5;
 
               var expectedDurationChangeEventCount = 1;
               var durationchangeEventCounter = 0;
               var durationchangeEventHandler = test.step_func(function(event)
               {
-                  assert_equals(mediaElement.duration, newDuration, 'mediaElement newDuration');
-                  assert_equals(mediaSource.duration, newDuration, 'mediaSource newDuration');
+                  assert_equals(mediaElement.duration, mediaSource.duration, 'mediaElement newDuration');
+                  // Final duration may be greater than originally set as per MSE's 2.4.6 Duration change
+                  // Adjust newDuration accordingly.
+                  assert_less_than_equal(newDuration, mediaSource.duration, 'mediaSource newDuration');
                   durationchangeEventCounter++;
               });
 
               mediaElement.play();
 
               // Append all the segments
               test.expectEvent(sourceBuffer, 'updateend', 'sourceBuffer');
               test.expectEvent(mediaElement, 'playing', 'Playing triggered');
               sourceBuffer.appendBuffer(mediaData);
 
               test.waitForExpectedEvents(function()
               {
-                  assert_equals(mediaElement.duration, fullDuration, 'mediaElement fullDuration');
-                  assert_equals(mediaSource.duration, fullDuration, 'mediaSource fullDuration');
                   assert_less_than(mediaElement.currentTime, newDuration / 2, 'mediaElement currentTime');
 
                   assert_false(sourceBuffer.updating, "updating");
 
                   // Truncate duration. This should result in one 'durationchange' fired.
                   sourceBuffer.remove(newDuration, Infinity);
 
                   assert_true(sourceBuffer.updating, "updating");
                   test.expectEvent(sourceBuffer, 'updatestart', 'sourceBuffer');
                   test.expectEvent(sourceBuffer, 'update', 'sourceBuffer');
                   test.expectEvent(sourceBuffer, 'updateend', 'sourceBuffer');
               });
 
               test.waitForExpectedEvents(function()
               {
-                  assert_equals(mediaElement.duration, fullDuration, 'mediaElement fullDuration');
-                  assert_equals(mediaSource.duration, fullDuration, 'mediaSource fullDuration');
-                  assert_less_than(mediaElement.currentTime, newDuration / 2, 'mediaElement currentTime');
-
                   // Media load also fires 'durationchange' event, so only start counting them now.
                   mediaElement.addEventListener('durationchange', durationchangeEventHandler);
 
                   assert_false(sourceBuffer.updating, "updating");
 
                   // Truncate duration. This should result in one 'durationchange' fired.
                   mediaSource.duration = newDuration;
-              });
-
-              test.waitForExpectedEvents(function()
-              {
-                  assert_false(sourceBuffer.updating, "updating");
 
                   // Final duration may be greater than originally set as per MSE's 2.4.6 Duration change
                   // Adjust newDuration accordingly.
                   assert_true(newDuration <= mediaSource.duration, 'adjusted duration');
                   newDuration = mediaSource.duration;
 
                   // Set duration again to make sure it does not trigger another 'durationchange' event.
                   mediaSource.duration = newDuration;