Transfer components of SurfaceId in OffscreenCanvas

third_party/WebKit/Source/core/offscreencanvas/OffscreenCanvas.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 OffscreenCanvas_h
 #define OffscreenCanvas_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
@@ skipping 29 matching lines @@
     bool isNeutered() const { return m_isNeutered; }
     void setNeutered();
     CanvasRenderingContext* getCanvasRenderingContext(ScriptState*, const String&, const CanvasContextCreationAttributes&);
     CanvasRenderingContext* renderingContext() { return m_context; }
 
     static void registerRenderingContextFactory(std::unique_ptr<CanvasRenderingContextFactory>);
 
     bool originClean() const;
     void setOriginTainted() { m_originClean = false; }
 
+    void setSurfaceId(uint32_t clientId, uint32_t localId, uint64_t nonce)
+    {
+        m_clientId = clientId;
+        m_localId = localId;
+        m_nonce = nonce;
+    }
+    uint32_t clientId() const { return m_clientId; }
+    uint32_t localId() const { return m_localId; }
+    uint64_t nonce() const { return m_nonce; }
+
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit OffscreenCanvas(const IntSize&);
 
     using ContextFactoryVector = Vector<std::unique_ptr<CanvasRenderingContextFactory>>;
     static ContextFactoryVector& renderingContextFactories();
     static CanvasRenderingContextFactory* getRenderingContextFactory(int);
 
     Member<CanvasRenderingContext> m_context;
     int m_canvasId = -1; // DOMNodeIds starts from 0, using -1 to indicate no associated canvas element.
     IntSize m_size;
     bool m_isNeutered = false;
 
     bool m_originClean;
+
+    // cc::SurfaceId is broken into three integer components as this can be used
+    // in transfer of OffscreenCanvas across threads
+    // If this object is not created via HTMLCanvasElement.transferControlToOffscreen(),
+    // then the following members would remain as initialized zero values.
+    uint32_t m_clientId = 0;
+    uint32_t m_localId = 0;
+    uint64_t m_nonce = 0;
 };
 
 } // namespace blink
 
 #endif // OffscreenCanvas_h