Refactor rtc_unittests into several targets.

webrtc/p2p/base/stun_unittest.cc

Index: webrtc/p2p/base/stun_unittest.cc
diff --git a/webrtc/p2p/base/stun_unittest.cc b/webrtc/p2p/base/stun_unittest.cc
index 033c5ddc6d89d8a1aa107c57b31a7f6b7ba55b72..1624e689d7f58cbdbab44a2b22819fcbfdbeb3dc 100644
--- a/webrtc/p2p/base/stun_unittest.cc
+++ b/webrtc/p2p/base/stun_unittest.cc
@@ -494,7 +494,7 @@ const in6_addr kIPv6TestAddress2 = { { { 0x24, 0x01, 0xfa, 0x00,
 const in_addr kIPv4TestAddress1 =  { 0xe64417ac };
 #elif defined WEBRTC_WIN
 // Windows in_addr has a union with a uchar[] array first.
-const in_addr kIPv4TestAddress1 =  { { 0x0ac, 0x017, 0x044, 0x0e6 } };
+const in_addr kIPv4TestAddress1 =  { { { 0x0ac, 0x017, 0x044, 0x0e6 } } };
 #endif
 const char kTestUserName1[] = "abcdefgh";
 const char kTestUserName2[] = "abc";