unittest step2: bye bye to multiple entrypoints for unittest

client/tests/client/dom/SVG2Test.dart

 #library('SVG2Test');
-#import('../../../../lib/unittest/unittest_dom.dart');
+#import('../../../../lib/unittest/unittest.dart');
+#import('../../../../lib/unittest/dom_config.dart');
 #import('dart:dom');
 
 // Test that SVG elements explicitly implement the IDL interfaces (is-checks
 // only, see SVGTest3 for behavioural tests).
 
 main() {
 
   insertTestDiv() {
     var element = document.createElement('div');
     element.innerHTML = @'''
 <svg id='svg1' width='200' height='100'>
 <rect id='rect1' x='10' y='20' width='130' height='40' rx='5'fill='blue'></rect>
 </svg>
 ''';
     document.body.appendChild(element);
     return element;
   }
 
-  forLayoutTests();
+  useDomConfiguration(isLayoutTest: true);
 
   test('rect_isChecks', () {
       var div = insertTestDiv();
       var r = document.getElementById('rect1');
 
       // Direct inheritance chain
       Expect.isTrue(r is SVGElement);
       Expect.isTrue(r is Element);
       Expect.isTrue(r is Node);
 
       // Other implemented interfaces.
       Expect.isTrue(r is SVGTests);
       Expect.isTrue(r is SVGLangSpace);
       Expect.isTrue(r is SVGExternalResourcesRequired);
       Expect.isTrue(r is SVGStylable);
       Expect.isTrue(r is SVGTransformable);
       Expect.isTrue(r is SVGLocatable);
 
       // Interfaces not implemented.
       Expect.isFalse(r is SVGNumber);
       Expect.isFalse(r is SVGRect);
       Expect.isFalse(r is SVGSVGElement);
 
       document.body.removeChild(div);
     });
 }