Only initialize NSS in PpapiPluginMain on !USE_OPENSSL builds.
This dates to https://chromiumcodereview.appspot.com/
11411013 which was added
to resolve the ClearKey CDM. ClearKey uses routines from //crypto which may use
NSS. But it doesn't need NSS in the chimera build, so we should limit this to
!USE_OPENSSL builds.
(The tests in question have also since moved to browser_tests and out of
//content.)
BUG=506323
Review URL: https://codereview.chromium.org/
1222103005
Cr-Commit-Position: refs/heads/master@{#337935}