Transfer components of SurfaceId in OffscreenCanvas

third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp

Index: third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp
diff --git a/third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp b/third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp
index 7119ec0471da0fe9edd446d70cd1586f478b6534..2e1dddeb0c9e7b80ca6e7409c7b887233dd62dcd 100644
--- a/third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp
+++ b/third_party/WebKit/Source/modules/canvas/HTMLCanvasElementModule.cpp
@@ -37,6 +37,13 @@ OffscreenCanvas* HTMLCanvasElementModule::transferControlToOffscreenInternal(HTM
     }
     OffscreenCanvas* offscreenCanvas = OffscreenCanvas::create(canvas.width(), canvas.height());
     offscreenCanvas->setAssociatedCanvasId(DOMNodeIds::idForNode(&canvas));
+
+    CanvasSurfaceLayerBridge* bridge = canvas.surfaceLayerBridge();
+    if (bridge) {
+        // If a bridge exists, it means canvas.createSurfaceLayer() has been called
+        // and its SurfaceId has been populated as well.
+        offscreenCanvas->setSurfaceId(bridge->getSurfaceId().client_id(), bridge->getSurfaceId().local_id(), bridge->getSurfaceId().nonce());
+    }
     return offscreenCanvas;
 }