Add flag to enable alternative services.

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 699002612e5efa11bfa7d235fa6e47393688dcc3..e29eedfd0cca1f84af14a6614e32e32615544bf8 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -522,6 +522,9 @@ const char kEnableQuic[]                    = "enable-quic";
 // This only has an effect if QUIC protocol is enabled.
 const char kEnableQuicPortSelection[]       = "enable-quic-port-selection";
 
+// Enables support for HTTP alternative services.
+const char kEnableAlternativeServices[] = "enable-alternative-services";
+
 // Enables save password prompt bubble.
 const char kEnableSavePasswordBubble[]      = "enable-save-password-bubble";