Introduce AXObjectCacheBase in core/ and remove WebNode dependency

third_party/WebKit/Source/core/dom/AXObjectCacheBase.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef AXObjectCacheBase_h
+#define AXObjectCacheBase_h
+
+#include "core/CoreExport.h"
+#include "core/dom/AXObjectCache.h"
+
+namespace blink {
+
+class Node;
+class AXObject;
+
+// AXObjectCacheBase is a temporary class that sits between AXObjectCache and
+// AXObjectImpl and contains methods required by web/ that we don't want to be
+// available in the public API (AXObjectCache).
+// TODO(dmazzoni): Once all dependencies in web/ use this class instead of
+// AXObjectCacheImpl, refactor usages to use AXObjectCache instead (introducing
+// new public API methods or similar) and remove this class.
+class CORE_EXPORT AXObjectCacheBase : public AXObjectCache {
+  WTF_MAKE_NONCOPYABLE(AXObjectCacheBase);
+
+ public:
+  virtual AXObject* Get(Node*) = 0;
+  ~AXObjectCacheBase() {}

[slangley, 2017/05/15 05:27:19]

Probably should be virtual right?

[sashab, 2017/05/15 05:50:22]

Done. Also moved it above the other method.

+
+ protected:
+  AXObjectCacheBase() : AXObjectCache(){};

[slangley, 2017/05/15 05:27:19]

Do we need this? I think it should automatically invoke the base class ctor when
there are no args? 

[sashab, 2017/05/15 05:50:22]

I get this error when I remove it:

../../third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp:94:20:
error: constructor for 'blink::AXObjectCacheImpl' must explicitly initialize the
base class 'blink::AXObjectCacheBase' which does not have a default constructor
AXObjectCacheImpl::AXObjectCacheImpl(Document& document)
                   ^
../../third_party/WebKit/Source/core/dom/AXObjectCacheBase.h:22:19: note:
'blink::AXObjectCacheBase' declared here
class CORE_EXPORT AXObjectCacheBase : public AXObjectCache {
                  ^
1 error generated.

I added it back, but removed the explicit call to the parent class.

+};
+
+// This is the only subclass of AXObjectCache.
+DEFINE_TYPE_CASTS(AXObjectCacheBase, AXObjectCache, cache, true, true);
+
+}  // namespace blink
+
+#endif