Adding a field trial for testing --force-compositing-mode on 50% of

chrome/browser/chrome_browser_main.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/browser/chrome_browser_main.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 142 matching lines @@
 #include "chrome/installer/util/install_util.h"
 #include "chrome/installer/util/shell_util.h"
 #include "net/base/net_util.h"
 #include "printing/printed_document.h"
 #include "ui/base/l10n/l10n_util_win.h"
 #endif  // defined(OS_WIN)
 
 #if defined(OS_MACOSX)
 #include <Security/Security.h>
 
+#include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "chrome/browser/mac/keystone_glue.h"
 #endif
 
 #if defined(ENABLE_RLZ)
 #include "chrome/browser/rlz/rlz.h"
 #endif
 
 #if defined(TOOLKIT_VIEWS)
 #include "ui/views/focus/accelerator_handler.h"
@@ skipping 339 matching lines @@
 const char kMissingLocaleDataTitle[] = "Missing File Error";
 const char kMissingLocaleDataMessage[] =
     "Unable to find locale data files. Please reinstall.";
 }  // namespace chrome_browser
 
 // BrowserMainParts ------------------------------------------------------------
 
 // static
 bool ChromeBrowserMainParts::disable_enforcing_cookie_policies_for_tests_ =
     false;
+bool ChromeBrowserMainParts::in_force_compositing_mode_trial_ = false;
 
 ChromeBrowserMainParts::ChromeBrowserMainParts(
     const content::MainFunctionParams& parameters)
     : parameters_(parameters),
       parsed_command_line_(parameters.command_line),
       result_code_(content::RESULT_CODE_NORMAL_EXIT),
       startup_watcher_(new StartupTimeBomb()),
       shutdown_watcher_(new ShutdownWatcherHelper()),
       record_search_engine_(false),
       translate_manager_(NULL),
@@ skipping 472 matching lines @@
   // Create a 100% field trial based on the brand code.
   if (auto_launch_trial::IsInExperimentGroup(brand)) {
     base::FieldTrialList::CreateFieldTrial(kAutoLaunchTrialName,
                                            kAutoLaunchTrialAutoLaunchGroup);
   } else if (auto_launch_trial::IsInControlGroup(brand)) {
     base::FieldTrialList::CreateFieldTrial(kAutoLaunchTrialName,
                                            kAutoLaunchTrialControlGroup);
   }
 }
 
+void ChromeBrowserMainParts::ForceCompositingModeFieldTrial() {
+// Enable the field trial only on the desktop OS's.
+#if !(defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX))
+  return;
+#endif
+  chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
+  // Only run the trial on the Canary channel.
+  if (channel != chrome::VersionInfo::CHANNEL_CANARY)
+    return;
+#if defined(OS_WIN)
+  // Don't run the trial on windows XP.

[Ilya Sherman, 2012/06/06 22:31:51]

nit: "windows" -> "Windows"

[vangelis, 2012/06/06 23:44:44]

Done.

+  if (base::win::GetVersion() < base::win::VERSION_VISTA)
+    return;
+#elif defined(OS_MACOSX)
+  // Accelerated compositing is only implemented on Mac OSX 10.6 or later.
+  if (base::mac::IsOSLeopardOrEarlier())
+    return;
+#endif
+
+  const base::FieldTrial::Probability kDivisor = 100;
+  scoped_refptr<base::FieldTrial> trial(
+    base::FieldTrialList::FactoryGetFieldTrial(
+        "ForceCompositingMode", kDivisor, "disable", 2012, 12, 31, NULL));
+
+  // Produce the same result on every run of this client.
+  trial->UseOneTimeRandomization();
+  // 50% probability of being in the enabled group.
+  const base::FieldTrial::Probability kEnableProbability = 50;
+  int enable_group = trial->AppendGroup("enable", kEnableProbability);
+
+  in_force_compositing_mode_trial_ = (trial->group() == enable_group);
+  UMA_HISTOGRAM_BOOLEAN("GPU.InForceCompositingModeFieldTrial",
+                        in_force_compositing_mode_trial_);
+}
+
 void ChromeBrowserMainParts::DomainBoundCertsFieldTrial() {
   chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
   if (channel == chrome::VersionInfo::CHANNEL_CANARY) {
     net::SSLConfigService::EnableDomainBoundCertsTrial();
   } else if (channel == chrome::VersionInfo::CHANNEL_DEV &&
              base::FieldTrialList::IsOneTimeRandomizationEnabled()) {
     const base::FieldTrial::Probability kDivisor = 100;
     // 10% probability of being in the enabled group.
     const base::FieldTrial::Probability kEnableProbability = 10;
     scoped_refptr<base::FieldTrial> trial =
@@ skipping 71 matching lines @@
   if (!proxy_policy_is_set)
     ProxyConnectionsFieldTrial();
   prerender::ConfigurePrefetchAndPrerender(parsed_command_line());
   SpdyFieldTrial();
   ConnectBackupJobsFieldTrial();
   WarmConnectionFieldTrial();
   PredictorFieldTrial();
   DefaultAppsFieldTrial();
   AutoLaunchChromeFieldTrial();
   DomainBoundCertsFieldTrial();
+  ForceCompositingModeFieldTrial();
   SetupUniformityFieldTrials();
   AutocompleteFieldTrial::Activate();
 }
 
 void ChromeBrowserMainParts::StartMetricsRecording() {
   MetricsService* metrics = g_browser_process->metrics_service();
   if (parsed_command_line_.HasSwitch(switches::kMetricsRecordingOnly) ||
       parsed_command_line_.HasSwitch(switches::kEnableBenchmarking)) {
     // If we're testing then we don't care what the user preference is, we turn
     // on recording, but not reporting, otherwise tests fail.
@@ skipping 890 matching lines @@
     if (base::win::GetVersion() <= base::win::VERSION_XP)
       uma_name += "_XP";
 
     uma_name += "_PreRead_";
     uma_name += pre_read_percentage;
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }