Support building BoringSSL with NSS certificates.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 6d3a6ed2458362665cba25a1058a88ec724a74b5..5a2c528c63ee5497ccf32795a876307dcc58f5a0 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -646,20 +646,12 @@
         }],
 
         # NSS usage.
-        ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris") and use_openssl==0', {
+        ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris")', {
           'use_nss%': 1,
         }, {
           'use_nss%': 0,
         }],
 
-        # When OpenSSL is used for SSL and crypto on Unix-like systems, use
-        # OpenSSL's certificate definition.
-        ['(OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris") and use_openssl==1', {
-          'use_openssl_certs%': 1,
-        }, {
-          'use_openssl_certs%': 0,
-        }],
-
         # libudev usage.  This currently only affects the content layer.
         ['OS=="linux" and embedded==0', {
           'use_udev%': 1,