Revert r59012 which started using Chrome sockets for sync.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 9d38d74b9969294ee4c19e61caf12a0df683076e..49626630c47c6cb90ce344843e9c944ffa3b1641 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -988,6 +988,11 @@ const char kStartMaximized[]                = "start-maximized";
 // Control Sync XMPP client settings.
 const char kSyncAllowPlain[]                = "allow-plain";
 
+// Disable the Chrome-socket-based buzz::AsyncSocket implementation
+// for sync notifications, instead using libjingle sockets.
+const char kSyncDisableChromeAsyncSocket[]  =
+    "sync-disable-chrome-async-socket";
+
 // Control Sync XMPP client settings.
 const char kSyncDisableTls[]                = "disable-tls";