Removing getBackingTextureImage from ImageBufferSurface

Source/platform/graphics/Canvas2DImageBufferSurface.h

Index: Source/platform/graphics/Canvas2DImageBufferSurface.h
diff --git a/Source/platform/graphics/Canvas2DImageBufferSurface.h b/Source/platform/graphics/Canvas2DImageBufferSurface.h
index 8bd12731d4f52bed49388476b0b8abde3c29f6c7..b027cec0b66c022594c62236dec65e5439e7d307 100644
--- a/Source/platform/graphics/Canvas2DImageBufferSurface.h
+++ b/Source/platform/graphics/Canvas2DImageBufferSurface.h
@@ -61,7 +61,6 @@ public:
     bool isValid() const override { return m_layerBridge && m_layerBridge->checkSurfaceValid(); }
     bool restore() override { return m_layerBridge->restoreSurface(); }
     WebLayer* layer() const override { return m_layerBridge->layer(); }
-    PassRefPtr<SkImage> getBackingTextureImage() const override { return m_layerBridge->getBackingTextureImage(); }
     bool isAccelerated() const override { return m_layerBridge->isAccelerated(); }
     void setFilterQuality(SkFilterQuality filterQuality) override { m_layerBridge->setFilterQuality(filterQuality); }
     void setIsHidden(bool hidden) override { m_layerBridge->setIsHidden(hidden); }