Support for Signal calls.

Merge in RedPhone

// FREEBIE

jni/webrtc/system_wrappers/interface/compile_assert_c.h

@@ -0,0 +1,22 @@
+/*
+ *  Copyright (c) 2012 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_SYSTEM_WRAPPERS_INTERFACE_COMPILE_ASSERT_H_
+#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_COMPILE_ASSERT_H_
+
+// Only use this for C files. For C++, use compile_assert.h.
+//
+// Use this macro to verify at compile time that certain restrictions are met.
+// The argument is the boolean expression to evaluate.
+// Example:
+//   COMPILE_ASSERT(sizeof(foo) < 128);
+#define COMPILE_ASSERT(expression) switch (0) {case 0: case expression:;}
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_COMPILE_ASSERT_H_