Add "Page ..." next to back and forward arrows

Tells the user which page they are on. This is already done on the
change list.

Bug: Issue 12108
Change-Id: Ic565cc76cc977955b71c12b9753b72c425b9f126

polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view.html

@@ -89,6 +89,7 @@ limitations under the License.
     </div>
     <slot></slot>
     <nav>
+      Page [[_computePage(offset, itemsPerPage)]]
       <a id="prevArrow"
           href$="[[_computeNavLink(offset, -1, itemsPerPage, filter, path)]]"
           hidden$="[[_hidePrevArrow(loading, offset)]]" hidden>

polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view.js

@@ -104,6 +104,13 @@
       const lastPage = items.length < this.itemsPerPage + 1;
       return lastPage;
     }
+
+    // TODO: fix offset (including itemsPerPage)
+    // to either support a decimal or make it go to the nearest
+    // whole number (e.g 3).
+    _computePage(offset, itemsPerPage) {
+      return offset / itemsPerPage + 1;
+    }
   }
 
   customElements.define(GrListView.is, GrListView);

polygerrit-ui/app/elements/shared/gr-list-view/gr-list-view_test.html

@@ -157,5 +157,10 @@ limitations under the License.
       element.path = TAGS_PATH;
       assert.equal(element._computeNavLink.lastCall.args[4], TAGS_PATH);
     });
+
+    test('_computePage', () => {
+      assert.equal(element._computePage(0, 25), 1);
+      assert.equal(element._computePage(50, 25), 3);
+    });
   });
 </script>