[Slimming Paint] Paint the inspector overlay with GraphicsLayer DisplayList.

public/web/WebGraphicsContext.h

Index: public/web/WebGraphicsContext.h
diff --git a/public/web/WebGraphicsContext.h b/public/web/WebGraphicsContext.h
new file mode 100644
index 0000000000000000000000000000000000000000..30053c6928e7d0ef2f56df65b86ab25a2b4f6929
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+++ b/public/web/WebGraphicsContext.h
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+// 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 WebGraphicsContext_h
+#define WebGraphicsContext_h
+
+#include "public/platform/WebCanvas.h"
+#include "public/platform/WebFloatRect.h"
+
+namespace blink {
+
+// Wraps a blink::GraphicsContext.
+// Internal consumers can extract the underlying context (via WebGraphicsContextImpl).
+// External consumers can make a single drawing using a WebCanvas.
+class WebGraphicsContext {

[Xianzhu, 2015/02/10 23:34:01]

Nit: Can we just make it a concrete class (like wrappers such as WebNode etc)?

[jbroman, 2015/02/11 00:32:54]

See reply to pdr's comment.

+public:
+    virtual WebCanvas* beginDrawing(const WebFloatRect& bounds) = 0;
+    virtual void endDrawing() = 0;
+
+protected:
+    ~WebGraphicsContext() { }
+};
+
+} // namespace blink
+
+#endif