Allow zoom/restore in a zoomed document. It is a regression from an earlier fix.

Source/core/html/ImageDocument.h

Index: Source/core/html/ImageDocument.h
diff --git a/Source/core/html/ImageDocument.h b/Source/core/html/ImageDocument.h
index e0fc4decacf96ae5f449ff68498c395d9747eb9e..b52f08f34e4b673a22e7ffe5bdd141f14ef4efa0 100644
--- a/Source/core/html/ImageDocument.h
+++ b/Source/core/html/ImageDocument.h
@@ -40,10 +40,15 @@ public:
         return adoptRefWillBeNoop(new ImageDocument(initializer));
     }
 
+    enum ScaleType {
+        ScaleZoomedDocument,
+        ScaleOnlyUnzoomedDocument
+    };
+
     ImageResource* cachedImage();
     HTMLImageElement* imageElement() const { return m_imageElement.get(); }
 
-    void windowSizeChanged();
+    void windowSizeChanged(ScaleType);
     void imageUpdated();
     void imageClicked(int x, int y);
 
@@ -58,8 +63,8 @@ private:
 #endif
 
     void createDocumentStructure();
-    void resizeImageToFit();
-    void restoreImageSize();
+    void resizeImageToFit(ScaleType);
+    void restoreImageSize(ScaleType);
     bool imageFitsInWindow() const;
     bool shouldShrinkToFit() const;
     float scale() const;