gpu: Add flag for enabling asynchronous worker context.

content/browser/compositor/gpu_process_transport_factory.cc

Index: content/browser/compositor/gpu_process_transport_factory.cc
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index f2bfa3e29e258f13b3f07839865f72018162f1af..308f8d351bbaa8e02cd296e3c95ef87124571829 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -131,7 +131,8 @@ scoped_refptr<content::ContextProviderCommandBuffer> CreateContextCommon(
   return make_scoped_refptr(new content::ContextProviderCommandBuffer(
       base::WrapUnique(new content::WebGraphicsContext3DCommandBufferImpl(
           surface_handle, url, gpu_channel_host.get(), gfx::PreferIntegratedGpu,
-          automatic_flushes)),
+          automatic_flushes, gpu::GPU_STREAM_DEFAULT,
+          gpu::GpuStreamPriority::NORMAL)),
       gpu::SharedMemoryLimits(), attributes, shared_context_provider, type));
 }