Always notify the MediaPlayer of any seek.

LayoutTests/media/media-controller-playbackrate.html

Index: LayoutTests/media/media-controller-playbackrate.html
diff --git a/LayoutTests/media/media-controller-playbackrate.html b/LayoutTests/media/media-controller-playbackrate.html
index e5a142b44a91494a8e26532d624c85a48e3cda43..e01f3420aa8b18e29cc1aa0e97d9bf179753d7c2 100644
--- a/LayoutTests/media/media-controller-playbackrate.html
+++ b/LayoutTests/media/media-controller-playbackrate.html
@@ -4,13 +4,15 @@
         <script src=media-file.js></script>
         <script src=video-test.js></script>
         <script>
-            var start = function() {
+            var start = function()
+            {
                 findMediaElement();
-                waitForEvent('canplay',canplay);
+                waitForEventOnce('canplay',canplay);
                 video.src = findMediaFile('video', 'content/test');
             };
 
-            var canplay = function() {
+            var canplay = function()
+            {
                 video.mediaGroup = "group";
 
                 // Test non-finite rates.
@@ -28,14 +30,19 @@
                 video.controller.defaultPlaybackRate = 0;
                 waitForEvent('play', play);
                 video.play();
+            };
+
+            var play = function()
+            {
+                video.controller.playbackRate = 2;
+                waitForEventOnce("playing", function()
+                {
+                    waitForEventOnce("timeupdate", timeupdate);
+                });
             };
 
-            var play = function() {
-                video.controller.playbackRate = 2;
-                waitForEventOnce('timeupdate', timeupdate);
-            };
-
-            var timeupdate = function() {
+            var timeupdate = function()
+            {
                 testExpected('video.currentTime', 0, '!=');
                 endTest();
             };