Add paint() function as valid CSS <image> type.

third_party/WebKit/Source/core/css/CSSPaintValue.h

Index: third_party/WebKit/Source/core/css/CSSPaintValue.h
diff --git a/third_party/WebKit/Source/core/css/CSSPaintValue.h b/third_party/WebKit/Source/core/css/CSSPaintValue.h
new file mode 100644
index 0000000000000000000000000000000000000000..905b5784f6fb561321beee84878a0e561f9527a2
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/CSSPaintValue.h
@@ -0,0 +1,49 @@
+// Copyright 2016 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 CSSPaintValue_h
+#define CSSPaintValue_h
+
+#include "core/css/CSSCustomIdentValue.h"
+#include "core/css/CSSImageGeneratorValue.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class CSSPaintValue : public CSSImageGeneratorValue {
+public:
+    static PassRefPtrWillBeRawPtr<CSSPaintValue> create(PassRefPtrWillBeRawPtr<CSSCustomIdentValue> name)
+    {
+        return adoptRefWillBeNoop(new CSSPaintValue(name));
+    }
+    ~CSSPaintValue();
+
+    String customCSSText() const;
+
+    String name() const;
+
+    PassRefPtr<Image> image(const LayoutObject*, const IntSize&);
+    bool isFixedSize() const { return false; }
+    IntSize fixedSize(const LayoutObject*) { return IntSize(); }
+
+    bool isPending() const { return false; }
+    bool knownToBeOpaque(const LayoutObject*) const { return false; }
+
+    void loadSubimages(Document*) { }
+
+    bool equals(const CSSPaintValue&) const;
+
+    DECLARE_TRACE_AFTER_DISPATCH();
+
+private:
+    explicit CSSPaintValue(PassRefPtrWillBeRawPtr<CSSCustomIdentValue> name);
+
+    RefPtrWillBeMember<CSSCustomIdentValue> m_name;
+};
+
+DEFINE_CSS_VALUE_TYPE_CASTS(CSSPaintValue, isPaintValue());
+
+} // namespace blink
+
+#endif // CSSPaintValue_h