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..4f4ab0fbf826f20926e0267ac46c617311e96c79 100644
--- a/webrtc/base/refcount.h
+++ b/webrtc/base/refcount.h
@@ -107,15 +107,24 @@ 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.
+  // TODO(nisse): Currently used only by
+  // I420BufferPool::PooledI420Buffer. Consider deleting once
+  // IsMutable is deleted, see
+  // https://bugs.chromium.org/p/webrtc/issues/detail?id=5921
+  virtual int GetRefCount() const {
+    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() {