Fix leak in X509UtilNSSTest VerifyCertificateSignature.
Fix leak in X509UtilNSSTest VerifyCertificateSignature.

Forgot to initialize the ScopedPLArenaPool, so the ASN1 functions were
leaking.

BUG=88782
TEST=memory bots
TBR=cpu@chromium.org

Review URL: http://codereview.chromium.org/8588015

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@110417 0039d316-1c4b-4281-b951-d872f2087c98

gavinp/chromium,adobe/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,adobe/chromium,ropik/chromium,adobe/chromium,ropik/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium