Enabled mulithreaded video decoding.
Enabled mulithreaded video decoding.

For simplicity we're going with two threads regardless of CPU architecture.  We measured performance gains even on P4s and if you have a multi-core machine you're golden.

Review URL: http://codereview.chromium.org/113386

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@16068 0039d316-1c4b-4281-b951-d872f2087c98

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