Add createGradient and createPattern to OffscreenCanvas2D in worker

third_party/WebKit/Source/modules/csspaint/PaintRenderingContext2D.h

 // Copyright 2016 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 PaintRenderingContext2D_h
 #define PaintRenderingContext2D_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "modules/ModulesExport.h"
 #include "modules/canvas2d/BaseRenderingContext2D.h"
@@ skipping 14 matching lines @@
     {
         return new PaintRenderingContext2D(std::move(imageBuffer));
     }
 
     // BaseRenderingContext2D
 
     // PaintRenderingContext2D doesn't have any pixel readback so the origin
     // is always clean, and unable to taint it.
     bool originClean() const final { return true; }
     void setOriginTainted() final { }
-    bool wouldTaintOrigin(CanvasImageSource*) final { return false; }
+    bool wouldTaintOrigin(CanvasImageSource*, ScriptState*) final { return false; }
 
     int width() const final;
     int height() const final;
 
     bool hasImageBuffer() const final { return m_imageBuffer.get(); }
     ImageBuffer* imageBuffer() const final { return m_imageBuffer.get(); }
 
     bool parseColorOrCurrentColor(Color&, const String& colorString) const final;
 
     SkCanvas* drawingCanvas() const final;
@@ skipping 21 matching lines @@
 
 private:
     explicit PaintRenderingContext2D(PassOwnPtr<ImageBuffer>);
 
     OwnPtr<ImageBuffer> m_imageBuffer;
 };
 
 } // namespace blink
 
 #endif // PaintRenderingContext2D_h