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

chrome/browser/chrome_browser_field_trials_mobile.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_mobile.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/tracked_objects.h"
 #include "build/build_config.h"
 
 #if defined(OS_ANDROID)
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #endif
 
 namespace chrome {
 
-void SetupMobileFieldTrials(const base::CommandLine& parsed_command_line) {
+void SetupMobileFieldTrials() {
 #if defined(OS_ANDROID)
-  prerender::ConfigurePrerender(parsed_command_line);
+  prerender::ConfigurePrerender();
 
   // Force-enable profiler timing depending on the field trial.
   if (base::FieldTrialList::FindFullName("ProfilerTiming") == "Enable")
     tracked_objects::ThreadData::EnableProfilerTiming();
 #endif
 }
 
 }  // namespace chrome