GitLab

- Added GetKey() and SetKey() in AesDecryptor.
- Moved static functions out of AesDecryptorTest to make them file scope functions.

BUG=none
TEST=media_unittests

Review URL: https://chromiumcodereview.appspot.com/10822013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148984 0039d316-1c4b-4281-b951-d872f2087c98