add HitTestCanvasResult Class instend of std::pair<Element*, String>

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 39 matching lines @@
 
 #define CanvasDefaultInterpolationQuality InterpolationLow
 
 namespace blink {
 
 class AffineTransform;
 class CanvasContextCreationAttributes;
 class CanvasRenderingContext;
 class CanvasRenderingContextFactory;
 class GraphicsContext;
+class HitTestCanvasResult;
 class HTMLCanvasElement;
 class Image;
 class ImageBitmapOptions;
 class ImageBuffer;
 class ImageBufferSurface;
 class ImageData;
 class IntSize;
 
 class CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContext;
 typedef CanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContextOrImageBitmapRenderingContext RenderingContext;
@@ skipping 123 matching lines @@
 
     static void registerRenderingContextFactory(std::unique_ptr<CanvasRenderingContextFactory>);
     void updateExternallyAllocatedMemory() const;
 
     void styleDidChange(const ComputedStyle* oldStyle, const ComputedStyle& newStyle);
 
     void notifyListenersCanvasChanged();
 
     // For Canvas HitRegions
     bool isSupportedInteractiveCanvasFallback(const Element&);
-    std::pair<Element*, String> getControlAndIdIfHitRegionExists(const LayoutPoint&);
+    HitTestCanvasResult* getControlAndIdIfHitRegionExists(const LayoutPoint&);
     String getIdFromControl(const Element*);
 
     // For OffscreenCanvas that controls this html canvas element
     CanvasSurfaceLayerBridge* surfaceLayerBridge() const { return m_surfaceLayerBridge.get(); }
     bool createSurfaceLayer();
 
     void detachContext() { m_context = nullptr; }
 
 protected:
     void didMoveToNewDocument(Document& oldDocument) override;
@@ skipping 49 matching lines @@
     // Used for OffscreenCanvas that controls this HTML canvas element
     std::unique_ptr<CanvasSurfaceLayerBridge> m_surfaceLayerBridge;
 
     int m_numFramesSinceLastRenderingModeSwitch;
     bool m_pendingRenderingModeSwitch;
 };
 
 } // namespace blink
 
 #endif // HTMLCanvasElement_h