gpu: Add flag for enabling asynchronous worker context.

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 ebb25eb4c8af6bfcab2c8f67d4627e1356ceb125..e587d751a3dedd59c33351b8add42aa139af5961 100644
--- a/content/browser/gpu/compositor_util.cc
+++ b/content/browser/gpu/compositor_util.cc
@@ -238,6 +238,18 @@ bool IsGpuRasterizationEnabled() {
   return false;
 }
 
+bool IsAsyncWorkerContextEnabled() {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(switches::kDisableGpuAsyncWorkerContext))
+    return false;
+  else if (command_line.HasSwitch(switches::kEnableGpuAsyncWorkerContext))
+    return true;
+
+  return false;
+}
+
 bool IsForceGpuRasterizationEnabled() {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();