Relanding 'Always notify the MediaPlayer of any seek' patch

LayoutTests/media/media-controller-effective-playback-rate.html

Index: LayoutTests/media/media-controller-effective-playback-rate.html
diff --git a/LayoutTests/media/media-controller-effective-playback-rate.html b/LayoutTests/media/media-controller-effective-playback-rate.html
index 5dbdc9419568ee12fec781537f90953ca745eb18..0a292b1162f54a11789b2a79b87b6ee795bc4e29 100644
--- a/LayoutTests/media/media-controller-effective-playback-rate.html
+++ b/LayoutTests/media/media-controller-effective-playback-rate.html
@@ -13,7 +13,7 @@
                 // Set the rate on the media element so playback won't move forward.
                 video.playbackRate = 0;
 
-                waitForEvent("canplay",canplay);
+                waitForEventOnce("canplay",canplay);
             };
 
             var canplay = function()
@@ -35,15 +35,14 @@
             {
                 // Initiate playback and verify that time moves forward.
                 run("video.play()");
-                waitForEventOnce("play", play);
+                waitForEventOnce("playing", function()
+                {
+                    waitForEventOnce("timeupdate", timeupdate);
+                });
             };
 
-            var play = function()
+            var timeupdate = function()
             {
-                waitForEventOnce("timeupdate", timeupdate);
-            };
-
-            var timeupdate = function() {
                 testExpected("video.currentTime", 0, "!=");
                 endTest();
             };