Clean up QUIC field trial parsing code.

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 89ca3b748ef2298f1348247eee8fc6f95621ba4d..d487b50d708712657ed266a765901b9e9b5df0f7 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -356,7 +356,6 @@ class IOThread : public content::BrowserThreadDelegate {
   // QUIC handshake.
   static bool ShouldEnableQuicPacing(
       const base::CommandLine& command_line,
-      base::StringPiece quic_trial_group,
       const VariationParameters& quic_trial_params);
 
   // Returns true if QUIC should always require handshake confirmation during
@@ -393,7 +392,6 @@ class IOThread : public content::BrowserThreadDelegate {
   // parsing any of the options, or if the default value should be used.
   static size_t GetQuicMaxPacketLength(
       const base::CommandLine& command_line,
-      base::StringPiece quic_trial_group,
       const VariationParameters& quic_trial_params);
 
   // Returns the QUIC versions specified by any flags in |command_line|