Some clean up of ContentView and ContentViewCore.

Some of it stems from the "hardware accelerated" flag in ContentViewCore
ctor but it's unused. The rest are unused functions on ContentView.

Review URL: https://codereview.chromium.org/135903013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246109 0039d316-1c4b-4281-b951-d872f2087c98
Update net/third_party/nss to NSS 3.15.5 Beta 2.

alpn.patch and paddingextension.patch have been committed in the NSS
upstream.

In addition to calling SSL_SetNextProtoNego, the SSL_ENABLE_NPN and
SSL_ENABLE_ALPN options need to be used to control whether each of
NPN and APLN will be negotiated. SSL_ENABLE_NPN is enabled by default,
but we enable it explicitly to be safe.

R=agl@chromium.org
BUG=331625
TEST=none

Review URL: https://codereview.chromium.org/142283002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246110 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246110