Add lightspeed experiments to disable gpu.

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 <string>
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/auto_launch_trial.h"
 #include "chrome/browser/google/google_brand.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/profiles/profiles_state.h"
 #include "chrome/browser/safe_browsing/safe_browsing_blocking_page.h"
 #include "chrome/browser/ui/app_list/app_list_util.h"
 #include "chrome/browser/ui/sync/one_click_signin_helper.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/variations/variations_util.h"
+#include "components/variations/variations_associated_data.h"
 #include "content/public/common/content_constants.h"
 #include "net/spdy/spdy_session.h"
 #include "ui/base/layout.h"
 
 namespace chrome {
 
 namespace {
 
 void AutoLaunchChromeFieldTrial() {
   std::string brand;
@@ skipping 23 matching lines @@
 }
 
 void DisableShowProfileSwitcherTrialIfNecessary() {
   // This trial is created by the VariationsService, but it needs to be disabled
   // if multi-profiles isn't enabled.
   base::FieldTrial* trial = base::FieldTrialList::Find("ShowProfileSwitcher");
   if (trial && !profiles::IsMultipleProfilesEnabled())
     trial->Disable();
 }
 
+void SetupLightSpeedTrials() {
+  std::map<std::string, std::string> params;
+  if (!variations::GetVariationParams("LightSpeed", &params))

[gab, 2015/03/10 19:42:12]

Why not use typical GetVariationParamValue("LightSpeed", "NoGpu")?

[Alexei Svitkine (slow), 2015/03/10 19:48:36]

This was setting up up multiple parameters in a previous patchset. If we will
end up adding more things here, it will be a smaller diff. (There are no
efficiency gains since GetVariationParamValue() does a copy of the map
internally anyway.)

[Alexei Svitkine (slow), 2015/03/11 15:57:08]

Done.

+    return;
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();

[gab, 2015/03/10 19:42:12]

Inline this below.

[Alexei Svitkine (slow), 2015/03/11 15:57:08]

Done.

+  if (ContainsKey(params, "NoGpu"))
+    command_line->AppendSwitch(switches::kDisableGpu);
+}
+
 }  // namespace
 
 void SetupDesktopFieldTrials(const base::CommandLine& parsed_command_line,
                              PrefService* local_state) {
   prerender::ConfigurePrerender(parsed_command_line);
   AutoLaunchChromeFieldTrial();
   SetupInfiniteCacheFieldTrial();
   DisableShowProfileSwitcherTrialIfNecessary();
+  SetupLightSpeedTrials();
   SetupShowAppLauncherPromoFieldTrial(local_state);
 }
 
 }  // namespace chrome