Implement the 'noopener' link relation.

content/test/data/click-noreferrer-links.html

Index: content/test/data/click-noreferrer-links.html
diff --git a/content/test/data/click-noreferrer-links.html b/content/test/data/click-noreferrer-links.html
index 9117f0525847219255d084e5bff6d73a8734dbb7..bed24248e920fc2fd776292a01a0feb4275125f2 100644
--- a/content/test/data/click-noreferrer-links.html
+++ b/content/test/data/click-noreferrer-links.html
@@ -22,11 +22,20 @@
     return simulateClick(document.getElementById("noref_and_tblank_link"));
   }
 
+  function clickNoOpenerTargetBlankLink() {
+    return simulateClick(document.getElementById("noopener_and_tblank_link"));
+  }
+
   function clickSameSiteNoRefTargetedLink() {
     return simulateClick(
         document.getElementById("samesite_noref_and_targeted_link"));
   }
 
+  function clickSameSiteNoOpenerTargetedLink() {
+    return simulateClick(
+        document.getElementById("samesite_noopener_and_targeted_link"));
+  }
+
   function clickSameSiteTargetedLink() {
     return simulateClick(document.getElementById("samesite_targeted_link"));
   }
@@ -43,6 +52,10 @@
     return simulateClick(document.getElementById("noref_link"));
   }
 
+  function clickNoOpenerLink() {
+    return simulateClick(document.getElementById("noopener_link"));
+  }
+
   function clickBlankTargetedLink() {
     return simulateClick(document.getElementById("blank_targeted_link"));
   }
@@ -106,6 +119,9 @@
 <a href="title2.html" id="samesite_noref_and_targeted_link"
    rel="noreferrer" target="foo">
   same-site rel=noreferrer and target=foo</a><br>
+<a href="title2.html" id="samesite_noopener_and_targeted_link"
+   rel="noopener" target="foo">
+  same-site rel=noopener and target=foo</a><br>
 <a href="navigate_opener.html" id="samesite_targeted_link" target="foo">
   same-site target=foo</a><br>
 <a href="title2.html" id="samesite_tblank_link" target="_blank">
@@ -120,10 +136,15 @@
 <a href="http://REPLACE/title2.html"
    id="noref_and_tblank_link" rel="noreferrer" target="_blank">
   rel=noreferrer and target=_blank</a><br>
+<a href="http://REPLACE/title2.html"
+   id="noopener_and_tblank_link" rel="noopener" target="_blank">
+  rel=noopener and target=_blank</a><br>
 <a href="http://REPLACE/title2.html" id="tblank_link"
    target="_blank">target=_blank</a><br>
 <a href="http://REPLACE/title2.html" id="noref_link"
    rel="noreferrer">rel=noreferrer</a><br>
+<a href="http://REPLACE/title2.html" id="noopener_link"
+   rel="noopener">rel=opener</a><br>
 
 
 <iframe id="frame1" src="frame_tree/1-1.html"></iframe>