[Cleanup] Remove the obsolete Prerender field trial.

chrome/common/chrome_switches.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/chrome_switches.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 
 namespace switches {
@@ skipping 902 matching lines @@
 // "--prerender-from-omnibox=auto". auto: Allow field trial selection.
 const char kPrerenderFromOmniboxSwitchValueAuto[] = "auto";
 //   disabled: No prerendering.
 const char kPrerenderFromOmniboxSwitchValueDisabled[] = "disabled";
 //   enabled: Guaranteed prerendering.
 const char kPrerenderFromOmniboxSwitchValueEnabled[] = "enabled";
 // Controls speculative prerendering of pages, and content prefetching. Both
 // are dispatched from <link rel=prefetch href=...> elements.
 const char kPrerenderMode[]                 = "prerender";
 // These are the values the kPrerenderMode switch may have, as in
-// "--prerender=auto".
-//   auto: Allow field trial selection for prerender.
-const char kPrerenderModeSwitchValueAuto[]  = "auto";
+// "--prerender=disabled".
 //   disabled: No prerendering.
 const char kPrerenderModeSwitchValueDisabled[] = "disabled";
 //   enabled: Prerendering.
 const char kPrerenderModeSwitchValueEnabled[] = "enabled";
 
 // Use IPv6 only for privet HTTP.
 const char kPrivetIPv6Only[]                   = "privet-ipv6-only";
 
 // Outputs the product version information and quit. Used as an internal api to
 // detect the installed version of Chrome on Linux.
@@ skipping 482 matching lines @@
 
 // -----------------------------------------------------------------------------
 // DO NOT ADD YOUR CRAP TO THE BOTTOM OF THIS FILE.
 //
 // You were going to just dump your switches here, weren't you? Instead, please
 // put them in alphabetical order above, or in order inside the appropriate
 // ifdef at the bottom. The order should match the header.
 // -----------------------------------------------------------------------------
 
 }  // namespace switches