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

chrome/browser/gpu_util.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/gpu_util.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/values.h"
 #include "base/version.h"
+#include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/gpu_blacklist.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/gpu_info.h"
 
 using content::GpuDataManager;
 using content::GpuFeatureType;
 
 namespace {
 
@@ skipping 280 matching lines @@
         status = "enabled";
         if (kGpuFeatureInfo[i].name == "webgl" &&
             (command_line.HasSwitch(switches::kDisableAcceleratedCompositing) ||
              (flags & content::GPU_FEATURE_TYPE_ACCELERATED_COMPOSITING)))
           status += "_readback";
         bool has_thread = CommandLine::ForCurrentProcess()->HasSwitch(
             switches::kEnableThreadedCompositing) &&
             (!CommandLine::ForCurrentProcess()->HasSwitch(
                 switches::kDisableThreadedCompositing));
         if (kGpuFeatureInfo[i].name == "compositing" &&
-            CommandLine::ForCurrentProcess()->HasSwitch(
-                switches::kForceCompositingMode))
+            (CommandLine::ForCurrentProcess()->HasSwitch(
+                 switches::kForceCompositingMode) ||
+                 chrome_browser_trials::g_in_force_compositing_mode_trial))
           status += "_force";
         if (kGpuFeatureInfo[i].name == "compositing" &&
             has_thread)
           status += "_threaded";
         if (kGpuFeatureInfo[i].name == "css_animation") {
           if (has_thread)
             status = "accelerated_threaded";
           else
             status = "accelerated";
         }
@@ skipping 180 matching lines @@
         kGpuBlacklistFeatureHistogramNamesWin[i],
         1, kNumWinSubVersions * kGpuFeatureNumStatus,
         kNumWinSubVersions * kGpuFeatureNumStatus + 1,
         base::Histogram::kUmaTargetedHistogramFlag);
     histogram_pointer->Add(GetGpuBlacklistHistogramValueWin(value));
 #endif
   }
 }
 
 }  // namespace gpu_util;