Add jsdoc for playbackperf test and webgl test in both 2019 and tip.

Change-Id: I72b766af97fe5256b4ecf50efaced020c0cf3930

js/tests/2019/playbackperfTest.js

@@ -102,6 +102,10 @@ var createTotalVideoFramesValidationTest = function(videoStream, frames) {
 
 createTotalVideoFramesValidationTest(Media.H264.Video1MB, 25);
 
+/**
+ * Ensure that browser is able to detect frame drops by correctly implementing
+ * the DroppedFrameCount API.
+ */
 var createFrameDropValidationTest = function(videoStream1, videoStream2) {
   var test = createPerfTest('FrameDrop', 'Media Playback Quality');
   test.prototype.title = 'Frame Drop Validation';
@@ -148,7 +152,10 @@ var createFrameDropValidationTest = function(videoStream1, videoStream2) {
 createFrameDropValidationTest(
     Media.H264.Webgl1080p60fps, Media.VP9.Webgl2160p60fps);
 
-
+/**
+ * Ensure no dropped frame is encountered during playback of specified media
+ * format in certain playback rate.
+ */
 var createPlaybackPerfTest = function(
     videoStream, playbackRate, category, optional) {
   var test = createPerfTest('PlaybackPerf' + '.' + videoStream.codec +

js/tests/2019/webglTest.js

@@ -15,6 +15,10 @@ limitations under the License.
  */
 'use strict';
 
+/**
+ * WebGL Performance Test Suite.
+ * @class
+ */
 var WebglTest = function() {
 
 var webkitPrefix = MediaSource.prototype.version.indexOf('webkit') >= 0;
@@ -52,7 +56,10 @@ function setupWebglTest(video, runner, videoStream) {
   return new WebglHandler(video, canvas);
 }
 
-
+/**
+ * Ensure WebGL performance of given video format by comparing the playback
+ * frame rate with threshold values.
+ */
 var createWebglPerformanceTest = function(videoStream) {
   var test = createWebglTest('WebGLPerformance' + '.' + videoStream.codec +
       '.' + videoStream.get('resolution') + videoStream.get('fps'),

js/tests/tip/playbackperfTest.js

@@ -102,6 +102,10 @@ var createTotalVideoFramesValidationTest = function(videoStream, frames) {
 
 createTotalVideoFramesValidationTest(Media.H264.Video1MB, 25);
 
+/**
+ * Ensure that browser is able to detect frame drops by correctly implementing
+ * the DroppedFrameCount API.
+ */
 var createFrameDropValidationTest = function(videoStream1, videoStream2) {
   var test = createPerfTest('FrameDrop', 'Media Playback Quality');
   test.prototype.title = 'Frame Drop Validation';
@@ -148,7 +152,10 @@ var createFrameDropValidationTest = function(videoStream1, videoStream2) {
 createFrameDropValidationTest(
     Media.H264.Webgl1080p60fps, Media.VP9.Webgl2160p60fps);
 
-
+/**
+ * Ensure no dropped frame is encountered during playback of specified media
+ * format in certain playback rate.
+ */
 var createPlaybackPerfTest = function(
     videoStream, playbackRate, category, optional) {
   var test = createPerfTest('PlaybackPerf' + '.' + videoStream.codec +

js/tests/tip/webglTest.js

@@ -15,6 +15,10 @@ limitations under the License.
  */
 'use strict';
 
+/**
+ * WebGL Performance Test Suite.
+ * @class
+ */
 var WebglTest = function() {
 
 var webkitPrefix = MediaSource.prototype.version.indexOf('webkit') >= 0;
@@ -52,7 +56,10 @@ function setupWebglTest(video, runner, videoStream) {
   return new WebglHandler(video, canvas);
 }
 
-
+/**
+ * Ensure WebGL performance of given video format by comparing the playback
+ * frame rate with threshold values.
+ */
 var createWebglPerformanceTest = function(videoStream) {
   var test = createWebglTest('WebGLPerformance' + '.' + videoStream.codec +
       '.' + videoStream.get('resolution') + videoStream.get('fps'),