Pepper takes ownership of a mailbox before passing it to the texture layer.

components/mus/gles2/command_buffer_impl.cc

Index: components/mus/gles2/command_buffer_impl.cc
diff --git a/components/mus/gles2/command_buffer_impl.cc b/components/mus/gles2/command_buffer_impl.cc
index 20018b111ddb3b76493cde55e7592b7d3d98b300..86fb239829c8efc9c63309be4f1dc121b0ac4b6d 100644
--- a/components/mus/gles2/command_buffer_impl.cc
+++ b/components/mus/gles2/command_buffer_impl.cc
@@ -137,7 +137,12 @@ void CommandBufferImpl::CreateStreamTexture(
   NOTIMPLEMENTED();
 }
 
-void CommandBufferImpl::ProduceFrontBuffer(const gpu::Mailbox& mailbox) {
+void CommandBufferImpl::TakeFrontBuffer(const gpu::Mailbox& mailbox) {
+  NOTIMPLEMENTED();
+}
+
+void CommandBufferImpl::ReturnFrontBuffer(const gpu::Mailbox& mailbox,
+                                          bool is_lost) {
   NOTIMPLEMENTED();
 }