implement openssl symmetric key
add AES derived key test

Also includes some build fixes.

BUG=None
TEST=./out/Debug/base_unittests --gtest_filter=SymmetricKey*

Review URL: http://codereview.chromium.org/4691003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65936 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/crypto/symmetric_key.h b/base/crypto/symmetric_key.h
index 3f2be76..97291666 100644
--- a/base/crypto/symmetric_key.h
+++ b/base/crypto/symmetric_key.h
@@ -66,8 +66,8 @@
 
  private:
 #if defined(USE_OPENSSL)
-  // TODO(joth): Add a constructor that accepts OpenSSL symmetric key data, and
-  // the appropriate data members to store it in.
+  SymmetricKey() {}
+  std::string key_;
 #elif defined(USE_NSS)
   explicit SymmetricKey(PK11SymKey* key);
   ScopedPK11SymKey key_;