Add CTS test for MimeUtils mp3 handling.

Bug: https://code.google.com/p/android/issues/detail?id=53598
Change-Id: I69d4927760a9a6037a13d0f37b94d60706b6c187
diff --git a/tests/tests/webkit/src/android/webkit/cts/MimeTypeMapTest.java b/tests/tests/webkit/src/android/webkit/cts/MimeTypeMapTest.java
index 7213184..6c0ff78 100644
--- a/tests/tests/webkit/src/android/webkit/cts/MimeTypeMapTest.java
+++ b/tests/tests/webkit/src/android/webkit/cts/MimeTypeMapTest.java
@@ -75,6 +75,7 @@
     }
 
     public void testGetExtensionFromMimeType() {
+        assertEquals("mp3", mMimeTypeMap.getExtensionFromMimeType("audio/mpeg"));
         assertEquals("png", mMimeTypeMap.getExtensionFromMimeType("image/png"));
         assertEquals("zip", mMimeTypeMap.getExtensionFromMimeType("application/zip"));