compositor-worker: Introduce WebCompositorMutableState

third_party/WebKit/public/platform/WebCompositorMutableState.h

+// Copyright 2015 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 WebCompositorMutableState_h
+#define WebCompositorMutableState_h
+
+#include <cstdint>
+
+class SkMatrix44;
+
+namespace blink {
+
+// This class wraps the compositor-owned, mutable state for a single element.
+class WebCompositorMutableState {
+public:
+    virtual ~WebCompositorMutableState() { }
+
+    virtual double opacity() const = 0;
+    virtual void setOpacity(double) = 0;
+
+    virtual const SkMatrix44& transform() const = 0;
+    virtual void setTransform(const SkMatrix44&) = 0;
+
+    virtual double scrollLeft() const = 0;
+    virtual void setScrollLeft(double) = 0;
+
+    virtual double scrollTop() const = 0;
+    virtual void setScrollTop(double) = 0;
+};
+
+} // namespace blink
+
+#endif // WebCompositorMutableState_h