Compile Opus for PNaCl

New target opus_untrusted compiles opus library for PNaCl.

BUG=276739

Review URL: https://codereview.chromium.org/116903003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241365 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241365
Remove RendererPreferences::browser_handles_all_top_level_link_clicks as it's
now unused (groby@ found a way to accomplish the same thing while using
RendererPreferences::browser_handles_non_local_top_level_requests).

Depends on: https://codereview.chromium.org/114503003

R=groby@chromium.org,jam@chromium.org
BUG=none
TEST=none

Review URL: https://codereview.chromium.org/116993002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241366 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241366