Add feature for main frame before activation.

content/browser/gpu/compositor_util.cc

Index: content/browser/gpu/compositor_util.cc
diff --git a/content/browser/gpu/compositor_util.cc b/content/browser/gpu/compositor_util.cc
index e587d751a3dedd59c33351b8add42aa139af5961..8d4091741dc9635142d921ff4a6121946ad9797a 100644
--- a/content/browser/gpu/compositor_util.cc
+++ b/content/browser/gpu/compositor_util.cc
@@ -7,6 +7,7 @@
 #include <stddef.h>
 
 #include "base/command_line.h"
+#include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/field_trial.h"
@@ -17,6 +18,7 @@
 #include "cc/base/switches.h"
 #include "content/browser/gpu/browser_gpu_memory_buffer_manager.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/config/gpu_feature_type.h"
 
@@ -281,6 +283,22 @@ int GpuRasterizationMSAASampleCount() {
   }
 }
 
+bool IsMainFrameBeforeActivationEnabled() {
+  if (base::SysInfo::NumberOfProcessors() < 4)
+    return false;
+
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(cc::switches::kDisableMainFrameBeforeActivation))
+    return false;
+
+  if (command_line.HasSwitch(cc::switches::kEnableMainFrameBeforeActivation))
+    return true;
+
+  return base::FeatureList::IsEnabled(features::kMainFrameBeforeActivation);
+}
+
 base::DictionaryValue* GetFeatureStatus() {
   GpuDataManagerImpl* manager = GpuDataManagerImpl::GetInstance();
   std::string gpu_access_blocked_reason;