Remove unnecessary param in function declaration & calls

There was previously a bug in the Youtube API that caused videos
to not play at a set speed in Safari. The bug has apparently since
been fixed, so we no longer need code for that browser
special case.

common/lib/xmodule/xmodule/js/spec/video/video_player_spec.js

@@ -436,7 +436,7 @@ function(VideoPlayer) {
                     state.speed = '2.0';
                     state.videoPlayer.onPlay();
                     expect(state.videoPlayer.setPlaybackRate)
-                        .toHaveBeenCalledWith('2.0', true);
+                        .toHaveBeenCalledWith('2.0');
                     state.videoPlayer.onPlay();
                     expect(state.videoPlayer.setPlaybackRate.calls.count())
                         .toEqual(1);
@@ -943,9 +943,8 @@ function(VideoPlayer) {
                 state.isHtml5Mode.and.returnValue(false);
                 state.videoPlayer.isPlaying.and.returnValue(true);
                 VideoPlayer.prototype.setPlaybackRate.call(state, '0.75');
-                expect(state.videoPlayer.updatePlayTime).toHaveBeenCalledWith(60);
-                expect(state.videoPlayer.player.loadVideoById)
-                    .toHaveBeenCalledWith('videoId', 60);
+                expect(state.videoPlayer.player.setPlaybackRate)
+                    .toHaveBeenCalledWith('0.75');
             });
 
             it('in Flash mode and video not started', function() {
@@ -953,15 +952,7 @@ function(VideoPlayer) {
                 state.isHtml5Mode.and.returnValue(false);
                 state.videoPlayer.isPlaying.and.returnValue(false);
                 VideoPlayer.prototype.setPlaybackRate.call(state, '0.75');
-                expect(state.videoPlayer.updatePlayTime).toHaveBeenCalledWith(60);
-                expect(state.videoPlayer.seekTo).toHaveBeenCalledWith(60);
-                expect(state.trigger).toHaveBeenCalledWith(
-                    'videoProgressSlider.updateStartEndTimeRegion',
-                    {
-                        duration: 60
-                    });
-                expect(state.videoPlayer.player.cueVideoById)
-                    .toHaveBeenCalledWith('videoId', 60);
+                expect(state.videoPlayer.player.setPlaybackRate).toHaveBeenCalledWith('0.75');
             });
 
             it('in HTML5 mode', function() {
@@ -975,9 +966,7 @@ function(VideoPlayer) {
 
                 state.videoPlayer.isPlaying.and.returnValue(false);
                 VideoPlayer.prototype.setPlaybackRate.call(state, '1.0');
-                expect(state.videoPlayer.updatePlayTime).toHaveBeenCalledWith(60);
-                expect(state.videoPlayer.player.cueVideoById)
-                    .toHaveBeenCalledWith('videoId', 60);
+                expect(state.videoPlayer.player.setPlaybackRate).toHaveBeenCalledWith('1.0');
             });
         });
     });

common/lib/xmodule/xmodule/js/src/video/03_video_player.js

@@ -109,16 +109,7 @@ function(HTML5Video, Resizer) {
         // starts playing. Just after that configurations can be applied.
         state.videoPlayer.ready = _.once(function() {
             if (!state.isFlashMode() && state.speed != '1.0') {
-                // Work around a bug in the Youtube API that causes videos to
-                // play at normal speed rather than at the configured speed in
-                // Safari.  Setting the playback rate to 1.0 *after* playing
-                // started and then to the actual value tricks the player into
-                // picking up the speed setting.
-                if (state.browserIsSafari && state.isYoutubeType()) {
-                    state.videoPlayer.setPlaybackRate(1.0, false);
-                }
-
-                state.videoPlayer.setPlaybackRate(state.speed, true);
+                state.videoPlayer.setPlaybackRate(state.speed);
             }
         });
 
@@ -381,10 +372,7 @@ function(HTML5Video, Resizer) {
         }
     }
 
-    function setPlaybackRate(newSpeed, useCueVideoById) {
-        var duration = this.videoPlayer.duration(),
-            time = this.videoPlayer.currentTime;
-
+    function setPlaybackRate(newSpeed) {
         this.videoPlayer.player.setPlaybackRate(newSpeed);
     }