Undo accidental dropping of dlls from skipped symbols.
Undo accidental dropping of dlls from skipped symbols.

https://chromiumcodereview.appspot.com/9417014/ accidentally dropped
avutil-51.dll from the skipped symbols list. This change adds it back.

BUG=110776
TEST=none


Review URL: http://codereview.chromium.org/9433050

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@123112 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build