Validate finiteness of HTMLMediaElement properties.

LayoutTests/media/video-playbackrate.html

Index: LayoutTests/media/video-playbackrate.html
diff --git a/LayoutTests/media/video-playbackrate.html b/LayoutTests/media/video-playbackrate.html
index 0ef2fc7ec897216e2d974269a49cedeceffcb57a..00ed637ea1cca87f8cea948817791beefbf8fa46 100644
--- a/LayoutTests/media/video-playbackrate.html
+++ b/LayoutTests/media/video-playbackrate.html
@@ -79,6 +79,18 @@
                 run("video.playbackRate = Number.MAX_VALUE");
                 testExpected("video.playbackRate", Number.MAX_VALUE);
                 consoleWrite("");
+
+                consoleWrite("Test non-finite playback rates");
+                testException("video.defaultPlaybackRate = -Infinity", '"TypeError: Failed to set the \'defaultPlaybackRate\' property on \'HTMLMediaElement\': The value provided is infinite."');
+                testException("video.defaultPlaybackRate = Infinity", '"TypeError: Failed to set the \'defaultPlaybackRate\' property on \'HTMLMediaElement\': The value provided is infinite."');
+                testException("video.defaultPlaybackRate = NaN", '"TypeError: Failed to set the \'defaultPlaybackRate\' property on \'HTMLMediaElement\': The value provided is not a number."');
+                consoleWrite("");
+
+                testException("video.playbackRate = -Infinity", '"TypeError: Failed to set the \'playbackRate\' property on \'HTMLMediaElement\': The value provided is infinite."');
+                testException("video.playbackRate = Infinity", '"TypeError: Failed to set the \'playbackRate\' property on \'HTMLMediaElement\': The value provided is infinite."');
+                testException("video.playbackRate = NaN", '"TypeError: Failed to set the \'playbackRate\' property on \'HTMLMediaElement\': The value provided is not a number."');
+                consoleWrite("");
+
                 endTest();
             }