Revert of Removing #defines previously used for building without BoringSSL/OpenSSL.

webrtc/base/messagedigest.cc

Index: webrtc/base/messagedigest.cc
diff --git a/webrtc/base/messagedigest.cc b/webrtc/base/messagedigest.cc
index 5e8621c77064cf2d58b3567853adfad75db5269f..c08cab4ea9db8c4120b89d6b0cdf9caca422c285 100644
--- a/webrtc/base/messagedigest.cc
+++ b/webrtc/base/messagedigest.cc
@@ -15,7 +15,13 @@
 #include <string.h>
 
 #include "webrtc/base/basictypes.h"
+#include "webrtc/base/sslconfig.h"
+#if SSL_USE_OPENSSL
 #include "webrtc/base/openssldigest.h"
+#else
+#include "webrtc/base/md5digest.h"
+#include "webrtc/base/sha1digest.h"
+#endif
 #include "webrtc/base/stringencode.h"
 
 namespace rtc {
@@ -31,12 +37,22 @@
 static const size_t kBlockSize = 64;  // valid for SHA-256 and down
 
 MessageDigest* MessageDigestFactory::Create(const std::string& alg) {
+#if SSL_USE_OPENSSL
   MessageDigest* digest = new OpenSSLDigest(alg);
   if (digest->Size() == 0) {  // invalid algorithm
     delete digest;
     digest = NULL;
   }
   return digest;
+#else
+  MessageDigest* digest = NULL;
+  if (alg == DIGEST_MD5) {
+    digest = new Md5Digest();
+  } else if (alg == DIGEST_SHA_1) {
+    digest = new Sha1Digest();
+  }
+  return digest;
+#endif
 }
 
 bool IsFips180DigestAlgorithm(const std::string& alg) {