gpu: Compositor management of GpuMemoryBuffer instances.

mojo/aura/surface_context_factory.cc

Index: mojo/aura/surface_context_factory.cc
diff --git a/mojo/aura/surface_context_factory.cc b/mojo/aura/surface_context_factory.cc
index 9f1e77a1735ad46d1835d472adcff9227a6507b5..aa964012ecd1a011e07313f53da5124d50c4da0f 100644
--- a/mojo/aura/surface_context_factory.cc
+++ b/mojo/aura/surface_context_factory.cc
@@ -52,6 +52,10 @@ cc::SharedBitmapManager* SurfaceContextFactory::GetSharedBitmapManager() {
   return nullptr;
 }
 
+cc::GpuMemoryBufferManager* SurfaceContextFactory::GetGpuMemoryBufferManager() {
+  return nullptr;
+}
+
 base::MessageLoopProxy* SurfaceContextFactory::GetCompositorMessageLoop() {
   return nullptr;
 }