Refactor ImageBuffer to make OffscreenCanvas match HTMLCanvasElement

third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h

Index: third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h b/third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h
index 77a01646caa4da16b88b1398c7cfaf8d227bcc07..0670f68f5becae5eb3a847dbeaba123cb660b53d 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h
+++ b/third_party/WebKit/Source/core/css/cssom/CSSStyleImageValue.h
@@ -41,7 +41,7 @@ class CORE_EXPORT CSSStyleImageValue : public CSSResourceValue,
   PassRefPtr<Image> GetSourceImageForCanvas(SourceImageStatus*,
                                             AccelerationHint,
                                             SnapshotReason,
-                                            const FloatSize&) const final {
+                                            const FloatSize&) final {
     return GetImage();
   }
   bool IsAccelerated() const override;