Update Context Client Visibility to use Scoped Pattern

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 31a899ea7a9b6d2a5c5f39c32220345f3ca564d6..edf362c9d5375db8b6f349b0c193e195199cdaeb 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -42,6 +42,7 @@
 #include "cc/trees/layer_tree_settings.h"
 #include "cc/trees/mutator_host_client.h"
 #include "cc/trees/task_runner_provider.h"
+#include "gpu/command_buffer/client/context_support.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace gfx {
@@ -840,6 +841,11 @@ class CC_EXPORT LayerTreeHostImpl
   std::unique_ptr<PendingTreeDurationHistogramTimer>
       pending_tree_duration_timer_;
 
+  std::unique_ptr<gpu::ContextSupport::ScopedVisibility>

[danakj, 2016/08/18 21:39:44]

can you put these right below the output_surface_?

[ericrk, 2016/08/19 17:23:19]

Done.

+      main_context_client_visibility_;
+  std::unique_ptr<gpu::ContextSupport::ScopedVisibility>
+      worker_context_client_visibility_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };