Issue 5264 - Return page objects instead of page IDs

ext/background.js

Index: ext/background.js
===================================================================
--- a/ext/background.js
+++ b/ext/background.js
@@ -21,55 +21,56 @@
 {
   let nonEmptyPageMaps = new Set();
 
   let PageMap = ext.PageMap = function()
   {
     this._map = new Map();
   };
   PageMap.prototype = {
-    _delete(id)
+    _deleteByPageId(id)
     {
-      this._map.delete(id);
-
-      if (this._map.size == 0)
-        nonEmptyPageMaps.delete(this);
+      for (let page of this.keys().filter(page => page.id == id))
+        this.delete(page);
     },
     keys()
     {
-      return this._map.keys();
+      return Array.from(this._map.keys());
     },
     get(page)
     {
-      return this._map.get(page.id);
+      return this._map.get(page);
     },
     set(page, value)
     {
-      this._map.set(page.id, value);
+      this._map.set(page, value);
       nonEmptyPageMaps.add(this);
     },
     has(page)
     {
-      return this._map.has(page.id);
+      return this._map.has(page);
     },
     clear()
     {
       this._map.clear();
       nonEmptyPageMaps.delete(this);
     },
     delete(page)
     {
-      this._delete(page.id);
+      this._map.delete(page);
+
+      if (this._map.size == 0)
+        nonEmptyPageMaps.delete(this);
     }
   };
 
   ext._removeFromAllPageMaps = pageId =>
   {
     for (let pageMap of nonEmptyPageMaps)
-      pageMap._delete(pageId);
+      pageMap._deleteByPageId(pageId);
   };
 
   /* Pages */
 
   let Page = ext.Page = function(tab)
   {
     this.id = tab.id;
     this._url = tab.url && new URL(tab.url);