Make canvas filters use the font size in effect when the filter is set

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 38 matching lines @@
     AffineTransform baseTransform() const final;
 
     void didDraw(const SkIRect& dirtyRect) final;
 
     // TODO(ikilpatrick): We'll need to either only accept resolved filters
     // from a typed-om <filter> object, or use the appropriate style resolution
     // host to determine 'em' units etc in filters. At the moment just pretend
     // that we don't have a filter set.
     bool stateHasFilter() final { return false; }
     SkImageFilter* stateGetFilter() final { return nullptr; }
+    void snapshotStateForFilter() final { }
 
     void validateStateStack() final;
 
     bool hasAlpha() const final { return true; }
 
     // PaintRenderingContext2D cannot lose it's context.
     bool isContextLost() const final { return false; }
 
 private:
     explicit PaintRenderingContext2D(PassOwnPtr<ImageBuffer>);
 
     OwnPtr<ImageBuffer> m_imageBuffer;
 };
 
 } // namespace blink
 
 #endif // PaintRenderingContext2D_h