MSE: Throw TypeError instead of InvalidAccessError per spec update

third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html

Index: third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html b/third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html
index 2fe975473577e630e711e79848d6ac0d7b5f6045..41ffd3ad4321aaac319d3e2dcdd31c4cb76df8fa 100644
--- a/third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html
+++ b/third_party/WebKit/LayoutTests/http/tests/media/media-source/mediasource-addsourcebuffer.html
@@ -26,7 +26,7 @@
 
           mediasource_test(function(test, mediaElement, mediaSource)
           {
-              assert_throws("InvalidAccessError",
+              assert_throws({name: "TypeError"},

[foolip, 2016/09/07 19:42:49]

This does what the spec asks, but I do wonder why the spec handled the empty
string separately instead of just letting NotSupportedError be thrown. If the
check is already implemented in other engines then I wouldn't go about changes
the spec, though.

[wolenetz, 2016/09/07 21:09:26]

Good point. I believe this is implemented in other UAs now (we'll see if that's
so in the upcoming implementation report). I also believe this was to enforce a
bare minimum bar that *something* must be in the string passed to
addSourceBuffer(). As we've seen, other UA's have been particularly lenient in
allowing underspecified mimetype/codec strings in both isTypeSupported() and
addSourceBuffer() vs Chrome's more strict take on it ala EME, so at least we
have this check :)

                           function() { mediaSource.addSourceBuffer(""); },
                           "addSourceBuffer() threw an exception when passed an empty string.");
               test.done();
@@ -39,7 +39,7 @@
                           "addSourceBuffer() threw an exception when passed null.");
               test.done();
           }, "Test addSourceBuffer() with null");
-          
+
           mediasource_test(function(test, mediaElement, mediaSource)
           {
               assert_throws("NotSupportedError",
@@ -90,7 +90,7 @@
               assert_equals(mediaSource.activeSourceBuffers.length, 0, "SourceBuffer is not in mediaSource.activeSourceBuffers");
               test.done();
           }, "Test addSourceBuffer() video only");
-          
+
           mediasource_test(function(test, mediaElement, mediaSource)
           {
               var mimetype = MediaSourceUtil.AUDIO_ONLY_TYPE;