Revert of purge nss files and dependencies

webrtc/base/sslstreamadapterhelper.h

 /*
  *  Copyright 2004 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.
  */
 
 #ifndef WEBRTC_BASE_SSLSTREAMADAPTERHELPER_H_
 #define WEBRTC_BASE_SSLSTREAMADAPTERHELPER_H_
 
 #include <string>
 #include <vector>
 
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/stream.h"
 #include "webrtc/base/sslidentity.h"
 #include "webrtc/base/sslstreamadapter.h"
 
 namespace rtc {
 
 // SSLStreamAdapterHelper : A stream adapter which implements much
 // of the logic that is common between the known implementations
-// (OpenSSL and previously NSS)
+// (NSS and OpenSSL)
 class SSLStreamAdapterHelper : public SSLStreamAdapter {
  public:
   explicit SSLStreamAdapterHelper(StreamInterface* stream);
   ~SSLStreamAdapterHelper() override;
 
   // Overrides of SSLStreamAdapter
   void SetIdentity(SSLIdentity* identity) override;
   void SetServerRole(SSLRole role = SSL_SERVER) override;
   void SetMode(SSLMode mode) override;
   void SetMaxProtocolVersion(SSLProtocolVersion version) override;
@@ skipping 71 matching lines @@
  private:
   // Go from state SSL_NONE to either SSL_CONNECTING or SSL_WAIT,
   // depending on whether the underlying stream is already open or
   // not. Returns 0 on success and a negative value on error.
   int StartSSL();
 };
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_SSLSTREAMADAPTERHELPER_H_