Replacing SurfaceReferenceBase and SequenceSurfaceReference with Closures

cc/surfaces/scoped_surface_reference_base.cc

Index: cc/surfaces/scoped_surface_reference_base.cc
diff --git a/cc/surfaces/surface_reference_base.cc b/cc/surfaces/scoped_surface_reference_base.cc
similarity index 69%
rename from cc/surfaces/surface_reference_base.cc
rename to cc/surfaces/scoped_surface_reference_base.cc
index 727e5ad6284542ce5d5b73787f69cebca3f15642..2e37d6066dfaf2ce33e24a4f573fdf5656c41ef0 100644
--- a/cc/surfaces/surface_reference_base.cc
+++ b/cc/surfaces/scoped_surface_reference_base.cc
@@ -2,21 +2,21 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "cc/surfaces/surface_reference_base.h"
+#include "cc/surfaces/scoped_surface_reference_base.h"
 
 #include "cc/surfaces/surface_reference_factory.h"
 
 namespace cc {
 
-SurfaceReferenceBase::SurfaceReferenceBase(
+ScopedSurfaceReferenceBase::ScopedSurfaceReferenceBase(
     scoped_refptr<const SurfaceReferenceFactory> factory)

[danakj, 2017/01/10 16:46:30]

why const?

     : factory_(std::move(factory)) {}
 
-SurfaceReferenceBase::~SurfaceReferenceBase() {
+ScopedSurfaceReferenceBase::~ScopedSurfaceReferenceBase() {
   DCHECK(!factory_) << "Each leaf subclass must call Destroy in its destructor";

[danakj, 2017/01/10 16:46:30]

Why do subclasses have to call it?

[Fady Samuel, 2017/01/10 18:14:01]

The data "SurfaceReference" or "SurfaceSequence" lives in the derived class. We
need to call "Destroy" before we destroy the data objects in the derived class,
thus Destroy must be called in the derived class. I agree though that callbacks
can accomplish what we want though without this subtlety.

 }
 
-void SurfaceReferenceBase::Destroy() {
+void ScopedSurfaceReferenceBase::Destroy() {
   factory_->DestroyReference(this);
   factory_ = nullptr;
 }