Revert "Ensure that diff property call backs are called immediately w…

…hen registered (dojo#572)"

This reverts commit b8b4678.

src/core/vdom.ts

@@ -878,7 +878,6 @@ export const diffProperty = factory(({ id }) => {
 			widgetMeta.customDiffProperties = widgetMeta.customDiffProperties || new Set();
 			const propertyDiffMap = widgetMeta.customDiffMap.get(id) || new Map();
 			if (!propertyDiffMap.has(propertyName)) {
-				diff({}, widgetMeta.properties);
 				propertyDiffMap.set(propertyName, diff);
 				widgetMeta.customDiffProperties.add(propertyName);
 			}

tests/core/unit/vdom.tsx

@@ -3790,6 +3790,7 @@ jsdomDescribe('vdom', () => {
 						let counter = 0;
 						const Foo = createWidget(({ middleware }) => {
 							middleware.diffProperty('key', (current: any, properties: any) => {
+								assert.deepEqual(current, { key: 'foo' });
 								assert.deepEqual(properties, { key: 'foo' });
 								middleware.invalidator();
 							});
@@ -3840,25 +3841,6 @@ jsdomDescribe('vdom', () => {
 						resolvers.resolve();
 						assert.strictEqual(root.outerHTML, '<div><div><button></button><div>first</div></div></div>');
 					});
-
-					it('should call diff property for the first render', () => {
-						const createWidget = create({ diffProperty });
-						let counter = 0;
-						const Foo = createWidget(({ middleware }) => {
-							middleware.diffProperty('key', () => {
-								counter++;
-							});
-							return v('div', [`${counter}`]);
-						});
-						const App = createWidget(() => {
-							return v('div', [v('button', {}), Foo({ key: 'foo' })]);
-						});
-						const r = renderer(() => App({}));
-						const root = document.createElement('div');
-						r.mount({ domNode: root });
-						assert.strictEqual(root.outerHTML, '<div><div><button></button><div>1</div></div></div>');
-						sendEvent(root.childNodes[0].childNodes[0] as HTMLButtonElement, 'click');
-					});
 				});
 			});
 		});