Fix race when HTMLMediaElement.play() is called just after pause().

third_party/WebKit/LayoutTests/media/media-play-promise.html

Index: third_party/WebKit/LayoutTests/media/media-play-promise.html
diff --git a/third_party/WebKit/LayoutTests/media/media-play-promise.html b/third_party/WebKit/LayoutTests/media/media-play-promise.html
index 77b4ac76d873b04ea315ffba91cc0df810ef6f1d..1ba5d608391223acb551f9c5a4cb44afff77c25f 100644
--- a/third_party/WebKit/LayoutTests/media/media-play-promise.html
+++ b/third_party/WebKit/LayoutTests/media/media-play-promise.html
@@ -105,6 +105,8 @@
             });
         },
 
+        // Test that play() on an element that is already playing returns a
+        // promise that resolves successfuly.

[fs, 2016/06/06 09:13:24]

Nit: successfully (also below)

[mlamouri (slow - plz ping), 2016/06/06 16:00:55]

Changed other places in the file.

         function playAfterPlaybackStarted()
         {
             consoleWrite("playAfterPlaybackStarted()");
@@ -391,7 +393,32 @@
                 run("mediaElement.volume = 0.2");
             });
 
-        }
+        },
+
+        // Test that calling pause() then play() on an element that is already
+        // playing returns a promise that resolves successfuly.
+        function pausePlayAfterPlaybackStarted()
+        {
+            consoleWrite("pausePlayAfterPlaybackStarted()");
+            internals.settings.setMediaPlaybackRequiresUserGesture(false);
+
+            run("mediaElement = document.createElement('audio')");
+            mediaElement.preload = "auto";
+            var mediaFile = findMediaFile("audio", "content/test");
+            run("mediaElement.src = '" + mediaFile + "'");
+
+            waitForEvent('playing', function() {
+                testExpected("mediaElement.readyState", HTMLMediaElement.HAVE_ENOUGH_DATA);
+                testExpected("mediaElement.paused", false);
+
+                run("mediaElement.pause()");
+                play();
+            });
+
+            waitForEvent('canplaythrough', function() {
+                run("mediaElement.play()");
+            });
+        },
     ];
 
     function start()