Implement authenticator based on SPAKE2 implementation in boringssl.

remoting/remoting.gyp

Index: remoting/remoting.gyp
diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index 79057768c017b464574591f1d6d71be6e0615edf..1b96b5279b577cb08369ca10c8bf85d541e34856 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -236,6 +236,7 @@
         '../crypto/crypto.gyp:crypto',
         '../jingle/jingle.gyp:jingle_glue',
         '../net/net.gyp:net',
+        '../third_party/boringssl/boringssl.gyp:boringssl',
         '../third_party/expat/expat.gyp:expat',
         '../third_party/libjingle/libjingle.gyp:libjingle',
         '../third_party/libyuv/libyuv.gyp:libyuv',
@@ -250,12 +251,21 @@
         '<@(remoting_signaling_sources)',
       ],
       'conditions': [
-        ['enable_webrtc==1', {
+        ['enable_webrtc == 1', {
           'dependencies': [
             '../third_party/libjingle/libjingle.gyp:libjingle_webrtc',
             '../third_party/libjingle/libjingle.gyp:libpeerconnection',
           ],
         }],
+        ['use_openssl == 0', {
+          'dependencies!': [
+            '../third_party/boringssl/boringssl.gyp:boringssl',
+          ],
+          'sources!': [
+            'protocol/spake2_authenticator.cc',
+            'protocol/spake2_authenticator.h',
+          ],
+        }],
       ],
     },  # end of target 'remoting_protocol'
   ],  # end of targets