Use createElement instead of HTML generation

Behind a feature flag. This is a relatively simple change; adopting this strategy universally would mean that we could clean up a lot of code but this doesn't attempt to restructure more than necessary.

src/test/ReactDefaultPerfAnalysis.js

@@ -23,8 +23,6 @@ var DOM_OPERATION_TYPES = {
   SET_MARKUP: 'set innerHTML',
   TEXT_CONTENT: 'set textContent',
   'updatePropertyByID': 'update attribute',
-  'deletePropertyByID': 'delete attribute',
-  'updateStylesByID': 'update styles',
   'dangerouslyReplaceNodeWithMarkupByID': 'replace',
 };
 

src/test/ReactTestUtils.js

@@ -399,7 +399,7 @@ ReactShallowRenderer.prototype.render = function(element, context) {
   if (!context) {
     context = emptyObject;
   }
-  var transaction = ReactUpdates.ReactReconcileTransaction.getPooled();
+  var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(false);
   this._render(element, transaction, context);
   ReactUpdates.ReactReconcileTransaction.release(transaction);
 };