Revert 12414.

tests/html/client_rect_test.dart

-#library('ClientRectTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
-
-main() {
-
-  insertTestDiv() {
-    var element = new Element.tag('div');
-    element.innerHTML = @'''
-    A large block of text should go here. Click this
-    block of text multiple times to see each line
-    highlight with every click of the mouse button.
-    ''';
-    document.body.nodes.add(element);
-    return element;
-  }
-
-  useHtmlConfiguration();
-
-   test("ClientRectList test", () {
-    insertTestDiv();
-    var range = document.createRange();
-    List<ClientRect> rects = range.getClientRects();
-    Expect.isTrue(rects is List<ClientRect>);
-  });
-}