Mozart: Generalize frame scheduling.

services/gfx/compositor/backend/gpu_output.cc

Index: services/gfx/compositor/backend/gpu_output.cc
diff --git a/services/gfx/compositor/backend/gpu_output.cc b/services/gfx/compositor/backend/gpu_output.cc
index cca044b12198c99fc855b68bf78539b9cd0a4fbe..3db57fe74fb355342aa45149529bb6041cd53b89 100644
--- a/services/gfx/compositor/backend/gpu_output.cc
+++ b/services/gfx/compositor/backend/gpu_output.cc
@@ -35,6 +35,7 @@ GpuOutput::GpuOutput(
     : compositor_task_runner_(base::MessageLoop::current()->task_runner()),
       vsync_scheduler_(
           new VsyncScheduler(compositor_task_runner_, scheduler_callbacks)),
+      error_callback_(error_callback),
       rasterizer_thread_(new base::Thread("gpu_rasterizer")),
       rasterizer_initialized_(true, false) {
   DCHECK(context_provider);