Bug 1072198 - updateBrowserRemoteness() needs to keep .permanentKey when updating browsers r=billm

browser/base/content/tabbrowser.xml

@@ -1449,8 +1449,12 @@
 
             // Change the "remote" attribute.
             let parent = aBrowser.parentNode;
+            let permanentKey = aBrowser.permanentKey;
             parent.removeChild(aBrowser);
             aBrowser.setAttribute("remote", aShouldBeRemote ? "true" : "false");
+            // Tearing down the browser gives a new permanentKey but we want to
+            // keep the old one. Re-set it explicitly after unbinding from DOM.
+            aBrowser.permanentKey = permanentKey;
             parent.appendChild(aBrowser);
 
             // Restore the progress listener.

browser/base/content/test/general/browser_e10s_switchbrowser.js

@@ -58,45 +58,54 @@ add_task(function*() {
   info("1");
   // Create a tab and load a remote page in it
   gBrowser.selectedTab = gBrowser.addTab("about:blank", {skipAnimation: true});
+  let {permanentKey} = gBrowser.selectedBrowser;
   yield waitForLoad("http://example.org/" + DUMMY_PATH);
   is(gBrowser.selectedTab.getAttribute("remote"), expectedRemote, "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
 
   info("2");
   // Load another page
   yield waitForLoad("http://example.com/" + DUMMY_PATH);
   is(gBrowser.selectedTab.getAttribute("remote"), expectedRemote, "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("3");
   // Load a non-remote page
   yield waitForLoad("about:robots");
   is(gBrowser.selectedTab.getAttribute("remote"), "", "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("4");
   // Load a remote page
   yield waitForLoad("http://example.org/" + DUMMY_PATH);
   is(gBrowser.selectedTab.getAttribute("remote"), expectedRemote, "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("5");
   yield back();
   is(gBrowser.selectedTab.getAttribute("remote"), "", "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("6");
   yield back();
   is(gBrowser.selectedTab.getAttribute("remote"), expectedRemote, "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("7");
   yield forward();
   is(gBrowser.selectedTab.getAttribute("remote"), "", "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("8");
   yield forward();
   is(gBrowser.selectedTab.getAttribute("remote"), expectedRemote, "Remote attribute should be correct");
+  is(gBrowser.selectedBrowser.permanentKey, permanentKey, "browser.permanentKey is still the same");
   check_history();
 
   info("9");

toolkit/content/widgets/browser.xml

@@ -386,8 +386,9 @@
 
       <field name="_permanentKey">({})</field>
 
-      <property name="permanentKey" readonly="true"
-                onget="return this._permanentKey;"/>
+      <property name="permanentKey"
+                onget="return this._permanentKey;"
+                onset="this._permanentKey = val;"/>
 
       <field name="_lastSearchString">null</field>
       <field name="_lastSearchHighlight">false</field>