FYI: Adds V8PrivateProperty::getOrUndefined().

third_party/WebKit/Source/bindings/core/v8/V8HiddenValue.h

 // Copyright 2014 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 V8HiddenValue_h
 #define V8HiddenValue_h
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/ScriptPromiseProperties.h"
 #include "core/CoreExport.h"
@@ skipping 25 matching lines @@
     V(internalBodyBuffer) \
     V(internalBodyStream) \
     V(port1) \
     V(port2) \
     V(readableStreamReaderInResponse) \
     V(state) \
     V(testInterfaces) \
     V(thenableHiddenPromise) \
     V(toStringString) \
     V(injectedScriptNative) \
-    V(webgl2DTextures) \
-    V(webgl2DArrayTextures) \
-    V(webgl3DTextures) \
-    V(webglAttachments) \
-    V(webglBuffers) \
-    V(webglCubeMapTextures) \
-    V(webglExtensions) \
-    V(webglMisc) \
-    V(webglQueries) \
-    V(webglSamplers) \
-    V(webglShaders) \
     SCRIPT_PROMISE_PROPERTIES(V, Promise)  \
     SCRIPT_PROMISE_PROPERTIES(V, Resolver)
 
 class CORE_EXPORT V8HiddenValue {
     USING_FAST_MALLOC(V8HiddenValue);
     WTF_MAKE_NONCOPYABLE(V8HiddenValue);
 public:
     static PassOwnPtr<V8HiddenValue> create() { return adoptPtr(new V8HiddenValue()); }
 
 #define V8_DECLARE_METHOD(name) static v8::Local<v8::String> name(v8::Isolate* isolate);
     V8_HIDDEN_VALUES(V8_DECLARE_METHOD);
 #undef V8_DECLARE_METHOD
 
     static v8::Local<v8::Value> getHiddenValue(ScriptState*, v8::Local<v8::Object>, v8::Local<v8::String>);
     static bool setHiddenValue(ScriptState*, v8::Local<v8::Object>, v8::Local<v8::String>, v8::Local<v8::Value>);
     static bool deleteHiddenValue(ScriptState*, v8::Local<v8::Object>, v8::Local<v8::String>);
     static v8::Local<v8::Value> getHiddenValueFromMainWorldWrapper(ScriptState*, ScriptWrappable*, v8::Local<v8::String>);
 
 private:
     V8HiddenValue() { }
 
 #define V8_DECLARE_FIELD(name) ScopedPersistent<v8::String> m_##name;
     V8_HIDDEN_VALUES(V8_DECLARE_FIELD);
 #undef V8_DECLARE_FIELD
 };
 
 } // namespace blink
 
 #endif // V8HiddenValue_h