Add support for GCM cipher suites from RFC 7714.

webrtc/base/helpers.h

Index: webrtc/base/helpers.h
diff --git a/webrtc/base/helpers.h b/webrtc/base/helpers.h
index 0e7937362a334c7cc29bc9a3ff203c1f7fec647c..7fef3d5eaeb53228f18ccb5d89d8bb5a4117e6d4 100644
--- a/webrtc/base/helpers.h
+++ b/webrtc/base/helpers.h
@@ -39,6 +39,10 @@ bool CreateRandomString(size_t length, std::string* str);
 bool CreateRandomString(size_t length, const std::string& table,
                         std::string* str);
 
+// Generates (cryptographically) random data of the given length.
+// Return false if the random number generator failed.
+bool CreateRandomData(size_t length, void* data);

[mattdr, 2016/05/10 22:29:13]

Let's avoid the buffer pointer and use a vector<char> or string.

e.g.

bool CreateRandomBytes(size_t length, string* bytes);

[joachim, 2016/05/10 23:09:44]

Done (used std::string).

+
 // Generates a (cryptographically) random UUID version 4 string.
 std::string CreateRandomUuid();