Don't block GPU process access in single-process mode.

content/browser/gpu/gpu_data_manager_impl_private.h

Index: content/browser/gpu/gpu_data_manager_impl_private.h
diff --git a/content/browser/gpu/gpu_data_manager_impl_private.h b/content/browser/gpu/gpu_data_manager_impl_private.h
index 97cd3808eab13d70afa0d26002a868244b97aeb4..c00d02dc1d413a72a2e08b40263ba29344e36983 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.h
+++ b/content/browser/gpu/gpu_data_manager_impl_private.h
@@ -269,6 +269,9 @@ class CONTENT_EXPORT GpuDataManagerImplPrivate {
   // True if all future Initialize calls should be ignored.
   bool finalized_;
 
+  // True if --single-process or --in-process-gpu is passed in.
+  bool in_process_gpu_;
+
   std::string disabled_extensions_;
 
   // If one tries to call a member before initialization then it is defered