Adjust AudioContextTest for Safari JS prototypes

Adjust AudioContextTest for Safari JS prototypes


BUG=

Committed: https://code.google.com/p/dart/source/detail?r=20186

[Emily Fortuna, 2013-03-18 23:44:26]

https://codereview.chromium.org/12802007/diff/2002/tests/html/audiocontext_te...
File tests/html/audiocontext_test.dart (right):

https://codereview.chromium.org/12802007/diff/2002/tests/html/audiocontext_te...
tests/html/audiocontext_test.dart:53: expect(context.createChannelMerger() is
AudioNode, isTrue);
this is for Safari. my guess is we're checking the JS prototype and in Safari
it's AudioNode and in CHrome it's ChannelMergerNode. Seems like the right thing
to do is to somehow see that ChannelMergerNode doesn't add anything as an API
and so we can say "no, really, it's also a ChannelMergerNode" but this interface
squashing can be done in the future.

[blois, 2013-03-18 23:45:37]

lgtm


But your CL description doesn't match the change.

[Emily Fortuna, 2013-03-18 23:46:58]

Committed patchset #1 manually as r20186 (presubmit successful).