Add deprecation message for -webkit-background-composite

third_party/WebKit/Source/core/frame/Deprecation.h

Index: third_party/WebKit/Source/core/frame/Deprecation.h
diff --git a/third_party/WebKit/Source/core/frame/Deprecation.h b/third_party/WebKit/Source/core/frame/Deprecation.h
new file mode 100644
index 0000000000000000000000000000000000000000..beb24bb709e4fd9b10a350ce46663aade8f2dd46
--- /dev/null
+++ b/third_party/WebKit/Source/core/frame/Deprecation.h
@@ -0,0 +1,37 @@
+// 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 Deprecation_h
+#define Deprecation_h
+
+#include "core/CSSPropertyNames.h"
+#include "wtf/BitVector.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class LocalFrame;
+
+class Deprecation {
+    DISALLOW_NEW();
+    WTF_MAKE_NONCOPYABLE(Deprecation);
+public:
+    Deprecation();
+    ~Deprecation();
+
+    static void warnOnDeprecatedProperties(const LocalFrame*, CSSPropertyID unresolvedProperty);
+    void clearSuppression();
+
+protected:
+    void suppress(CSSPropertyID unresolvedProperty);
+    bool isSuppressed(CSSPropertyID unresolvedProperty);
+    // CSSPropertyIDs that aren't deprecated return an empty string.
+    static String deprecationMessage(CSSPropertyID unresolvedProperty);
+
+    BitVector m_cssPropertyDeprecationBits;
+};
+
+} // namespace blink
+
+#endif // Deprecation_h