[Prerender] Get the prerender mode from Finch field trial.

chrome/browser/chrome_browser_field_trials_desktop.cc

 // Copyright 2013 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/browser/chrome_browser_field_trials_desktop.h"
 
 #include <map>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 88 matching lines @@
   // Track code activities (such as posting task, blocking on locks, and
   // joining threads) that can cause hanging threads and general instability
   base::debug::GlobalActivityTracker::CreateWithFile(
       stability_file, kMemorySize, kAllocatorId,
       browser_watcher::kStabilityDebuggingFeature.name, kStackDepth);
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace
 
-void SetupDesktopFieldTrials(const base::CommandLine& parsed_command_line) {
-  prerender::ConfigurePrerender(parsed_command_line);
+void SetupDesktopFieldTrials() {
+  prerender::ConfigurePrerender();
   SetupStunProbeTrial();
 #if defined(OS_WIN)
   SetupStabilityDebugging();
 #endif  // defined(OS_WIN)
 }
 
 }  // namespace chrome