Don't always fully repaint on viewport resize

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index 6de1d69fd6e38d8c91de3b2be9a35d255821d46b..cdd43c99caba084889a4b054033114ad597cc167 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -405,6 +405,8 @@ public:
 
     bool hasBackgroundImage() const { return m_background->background().hasImage(); }
     bool hasFixedBackgroundImage() const { return m_background->background().hasFixedImage(); }
+    bool backgroundImageNeedsFullRepaintOnContainerWidthChange() const { return m_background->background().needsFullRepaintOnContainerWidthChange(); }
+    bool backgroundImageNeedsFullRepaintOnContainerHeightChange() const { return m_background->background().needsFullRepaintOnContainerHeightChange(); }
 
     bool hasEntirelyFixedBackground() const;