Remove orphaned files.

webrtc/base/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/crypto.gni")
 import("//build/config/ui.gni")
@@ skipping 302 matching lines @@
     "ssladapter.cc",
     "ssladapter.h",
     "sslfingerprint.cc",
     "sslfingerprint.h",
     "sslidentity.cc",
     "sslidentity.h",
     "sslsocketfactory.cc",
     "sslsocketfactory.h",
     "sslstreamadapter.cc",
     "sslstreamadapter.h",
-    "sslstreamadapterhelper.cc",
-    "sslstreamadapterhelper.h",
     "stream.cc",
     "stream.h",
     "task.cc",
     "task.h",
     "taskparent.cc",
     "taskparent.h",
     "taskrunner.cc",
     "taskrunner.h",
     "thread.cc",
     "thread.h",
@@ skipping 320 matching lines @@
       "objc/RTCUIApplication.mm",
     ]
   }
 }
 
 source_set("gtest_prod") {
   sources = [
     "gtest_prod_util.h",
   ]
 }