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diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/note-grain-on-play.html b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/note-grain-on-play.html
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+++ b/testing/web-platform/tests/webaudio/the-audio-api/the-audiobuffersourcenode-interface/note-grain-on-play.html
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+<!DOCTYPE html>
+<html>
+  <head>
+    <title>
+      note-grain-on-play.html
+    </title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/webaudio/resources/audit-util.js"></script>
+    <script src="/webaudio/resources/audit.js"></script>
+    <script src="/webaudio/resources/note-grain-on-testing.js"></script>
+  </head>
+  <body>
+    <div id="description"></div>
+    <div id="console"></div>
+    <script id="layout-test-code">
+      let audit = Audit.createTaskRunner();
+
+      // To test noteGrainOn, a single ramp signal is created.
+      // Various sections of the ramp are rendered by noteGrainOn() at
+      // different times, and we verify that the actual output
+      // consists of the correct section of the ramp at the correct
+      // time.
+
+      let linearRampBuffer;
+
+      // Array of the grain offset used for each ramp played.
+      let grainOffsetTime = [];
+
+      // Verify the received signal is a ramp from the correct section
+      // of our ramp signal.
+      function verifyGrain(renderedData, startFrame, endFrame, grainIndex) {
+        let grainOffsetFrame =
+            timeToSampleFrame(grainOffsetTime[grainIndex], sampleRate);
+        let grainFrameLength = endFrame - startFrame;
+        let ramp = linearRampBuffer.getChannelData(0);
+        let isCorrect = true;
+
+        let expected;
+        let actual;
+        let frame;
+
+        for (let k = 0; k < grainFrameLength; ++k) {
+          if (renderedData[startFrame + k] != ramp[grainOffsetFrame + k]) {
+            expected = ramp[grainOffsetFrame + k];
+            actual = renderedData[startFrame + k];
+            frame = startFrame + k;
+            isCorrect = false;
+            break;
+          }
+        }
+        return {
+          verified: isCorrect,
+          expected: expected,
+          actual: actual,
+          frame: frame
+        };
+      }
+
+      function checkResult(buffer, should) {
+        renderedData = buffer.getChannelData(0);
+        let nSamples = renderedData.length;
+
+        // Number of grains that we found that have incorrect data.
+        let invalidGrainDataCount = 0;
+
+        let startEndFrames = findStartAndEndSamples(renderedData);
+
+        // Verify the start and stop times.  Not strictly needed for
+        // this test, but it's useful to know that if the ramp data
+        // appears to be incorrect.
+        verifyStartAndEndFrames(startEndFrames, should);
+
+        // Loop through each of the rendered grains and check that
+        // each grain contains our expected ramp.
+        for (let k = 0; k < startEndFrames.start.length; ++k) {
+          // Verify that the rendered data matches the expected
+          // section of our ramp signal.
+          let result = verifyGrain(
+              renderedData, startEndFrames.start[k], startEndFrames.end[k], k);
+          should(result.verified, 'Pulse ' + k + ' contained the expected data')
+              .beTrue();
+        }
+        should(
+            invalidGrainDataCount,
+            'Number of grains that did not contain the expected data')
+            .beEqualTo(0);
+      }
+
+      audit.define(
+          {
+            label: 'note-grain-on-play',
+            description: 'Test noteGrainOn offset rendering'
+          },
+          function(task, should) {
+            // Create offline audio context.
+            context =
+                new OfflineAudioContext(2, sampleRate * renderTime, sampleRate);
+
+            // Create a linear ramp for testing noteGrainOn.
+            linearRampBuffer = createSignalBuffer(context, function(k) {
+              // Want the ramp to start
+              // with 1, not 0.
+              return k + 1;
+            });
+
+            let grainInfo =
+                playAllGrains(context, linearRampBuffer, numberOfTests);
+
+            grainOffsetTime = grainInfo.grainOffsetTimes;
+
+            context.startRendering().then(function(audioBuffer) {
+              checkResult(audioBuffer, should);
+              task.done();
+            });
+          });
+
+      audit.run();
+    </script>
+  </body>
+</html>