feat(animate): adds basic support for CSS animations on enter and leave

Closes #3876

modules/angular2/src/mock/animation_builder_mock.ts

@@ -0,0 +1,33 @@
+import {Injectable} from 'angular2/src/core/di';
+import {AnimationBuilder} from 'angular2/src/animate/animation_builder';
+import {CssAnimationBuilder} from 'angular2/src/animate/css_animation_builder';
+import {CssAnimationOptions} from 'angular2/src/animate/css_animation_options';
+import {Animation} from 'angular2/src/animate/animation';
+import {BrowserDetails} from 'angular2/src/animate/browser_details';
+
+@Injectable()
+export class MockAnimationBuilder extends AnimationBuilder {
+  constructor() { super(null); }
+  css(): MockCssAnimationBuilder { return new MockCssAnimationBuilder(); }
+}
+
+class MockCssAnimationBuilder extends CssAnimationBuilder {
+  constructor() { super(null); }
+  start(element: HTMLElement): Animation { return new MockAnimation(element, this.data); }
+}
+
+class MockBrowserAbstraction extends BrowserDetails {
+  doesElapsedTimeIncludesDelay(): void { this.elapsedTimeIncludesDelay = false; }
+}
+
+class MockAnimation extends Animation {
+  private _callback: Function;
+  constructor(element: HTMLElement, data: CssAnimationOptions) {
+    super(element, data, new MockBrowserAbstraction());
+  }
+  wait(callback: Function) { this._callback = callback; }
+  flush() {
+    this._callback(0);
+    this._callback = null;
+  }
+}