Only use BoringSSL time callback in unit tests.

webrtc/base/opensslstreamadapter.h

Index: webrtc/base/opensslstreamadapter.h
diff --git a/webrtc/base/opensslstreamadapter.h b/webrtc/base/opensslstreamadapter.h
index 76ff2183a04524e14a830d3df04399f8bc5829b1..e7d2174be8e16c0a7437715964d6750111d45279 100644
--- a/webrtc/base/opensslstreamadapter.h
+++ b/webrtc/base/opensslstreamadapter.h
@@ -118,6 +118,10 @@ class OpenSSLStreamAdapter : public SSLStreamAdapter {
   static bool IsAcceptableCipher(int cipher, KeyType key_type);
   static bool IsAcceptableCipher(const std::string& cipher, KeyType key_type);
 
+  // Use our timeutils.h source of timing in BoringSSL, allowing us to test
+  // using a fake clock.
+  static void enable_time_callback_for_testing();
+
  protected:
   void OnEvent(StreamInterface* stream, int events, int err) override;