Integrate custom paint with the DocumentLifecycle

sky/engine/core/painting/PaintingTasks.h

Index: sky/engine/core/painting/PaintingTasks.h
diff --git a/sky/engine/core/painting/PaintingTasks.h b/sky/engine/core/painting/PaintingTasks.h
new file mode 100644
index 0000000000000000000000000000000000000000..792477c05b086170d18f7c8e70fbecb7905b2a29
--- /dev/null
+++ b/sky/engine/core/painting/PaintingTasks.h
@@ -0,0 +1,31 @@
+// 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 SKY_ENGINE_CORE_PAINTING_PAINTINGTASKS_H_
+#define SKY_ENGINE_CORE_PAINTING_PAINTINGTASKS_H_
+
+#include "sky/engine/wtf/PassOwnPtr.h"
+#include "sky/engine/wtf/PassRefPtr.h"
+
+namespace blink {
+class DisplayList;
+class Element;
+class PaintingCallback;
+
+class PaintingTasks {
+public:
+    static void enqueueRequest(PassRefPtr<Element>, PassOwnPtr<PaintingCallback>);
+    static void enqueueCommit(PassRefPtr<Element>, PassRefPtr<DisplayList>);
+
+    static bool serviceRequests();
+    static void drainCommits();
+
+private:
+    PaintingTasks() = delete;
+    ~PaintingTasks() = delete;
+};
+
+} // namespace blink
+
+#endif  // SKY_ENGINE_CORE_PAINTING_PAINTINGTASKS_H_