Reimplement PooledI420Buffer, without an extra indirection.

webrtc/base/refcount.h

Index: webrtc/base/refcount.h
diff --git a/webrtc/base/refcount.h b/webrtc/base/refcount.h
index 55ce23a348b68a84ce362d98f85c0f871725303a..550a7122ae2fe9c2f6c22d4ad506cd329c59596f 100644
--- a/webrtc/base/refcount.h
+++ b/webrtc/base/refcount.h
@@ -107,15 +107,20 @@ class RefCountedObject : public T {
     return count;
   }
 
+  // This call returns the reference count, and performs the memory
+  // barrier needed for the owning thread to act on the object, in
+  // case the value of the reference count implies exclusive access to
+  // the object.
+  virtual int GetRefCount() const {

[pbos-webrtc, 2016/05/20 13:32:21]

I think this method should also be going away, so pref adding a TODO to remove
it here?

[nisse-webrtc, 2016/05/23 07:35:06]

I can add a TODO like "Currently used only for I420PooledBuffer::IsMutable,
consider deleting when IsMutable is deleted." But I think it might be useful for
debugging, I remember I've been wanting to call it from gdb sometime.

+    return AtomicOps::AcquireLoad(&ref_count_);
+  }
   // Return whether the reference count is one. If the reference count is used
   // in the conventional way, a reference count of 1 implies that the current
   // thread owns the reference and no other thread shares it. This call
   // performs the test for a reference count of one, and performs the memory
   // barrier needed for the owning thread to act on the object, knowing that it
   // has exclusive access to the object.
-  virtual bool HasOneRef() const {
-    return AtomicOps::AcquireLoad(&ref_count_) == 1;
-  }
+  virtual bool HasOneRef() const { return GetRefCount() == 1; }
 
  protected:
   virtual ~RefCountedObject() {