Require the entire document-tree of an SVGImage to be single-origin

LayoutTests/canvas/resources/svg-with-multiple-feimage-one-with-foreignobject.svg

Index: LayoutTests/canvas/resources/svg-with-multiple-feimage-one-with-foreignobject.svg
diff --git a/LayoutTests/canvas/resources/svg-with-feimage-with-foreignobject.svg b/LayoutTests/canvas/resources/svg-with-multiple-feimage-one-with-foreignobject.svg
similarity index 75%
copy from LayoutTests/canvas/resources/svg-with-feimage-with-foreignobject.svg
copy to LayoutTests/canvas/resources/svg-with-multiple-feimage-one-with-foreignobject.svg
index bea47accfbb93cea7eb4748db9cca053a02e7152..356b176fc8ea440c45c91d6cfd30000a8e461880 100644
--- a/LayoutTests/canvas/resources/svg-with-feimage-with-foreignobject.svg
+++ b/LayoutTests/canvas/resources/svg-with-multiple-feimage-one-with-foreignobject.svg
@@ -3,8 +3,14 @@
 <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="100" height="100">
   <defs>
     <filter id="image">
-      <feImage xlink:href="data:image/svg+xml;charset=utf-8;base64,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">
-      </feImage>
+      <feImage xlink:href="data:image/gif;base64,R0lGODdhAQABAIABAACAAP///ywAAAAAAQABAAACAkQBADs=" result="r1"/>
+      <feImage xlink:href="data:image/svg+xml;charset=utf-8;base64,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" result="r2"/>
+      <feImage xlink:href="data:image/gif;base64,R0lGODdhAQABAIABAACAAP///ywAAAAAAQABAAACAkQBADs=" result="r3"/>
+      <feMerge>
+        <feMergeNode in="r1"/>
+        <feMergeNode in="r2"/>
+        <feMergeNode/>
+      </feMerge>
     </filter>
   </defs>
   <rect x="0" y="0" width="200" height="200" filter="url(#image)"/>