fix(animations): ensure the web-animations driver converts style props to camel-case

The web animations API now requires that all styles are converted to
camel case. Chrome has already made this breaking change and hyphenated
styles are not functional anymore.

Closes #9111
Closes #9112

modules/@angular/platform-browser/testing/mock_dom_animate_player.ts

@@ -0,0 +1,35 @@
+import {DomAnimatePlayer} from '../src/dom/dom_animate_player';
+import {isPresent} from '../src/facade/lang';
+
+export class MockDomAnimatePlayer implements DomAnimatePlayer {
+  public captures: {[key: string]: any[]} = {};
+  private _position: number = 0;
+  private _onfinish: Function = () => {};
+  public currentTime: number;
+
+  /** @internal */
+  _capture(method: string, data: any): void {
+    if (!isPresent(this.captures[method])) {
+      this.captures[method] = [];
+    }
+    this.captures[method].push(data);
+  }
+
+  cancel(): void { this._capture('cancel', null); }
+  play(): void { this._capture('play', null); }
+  pause(): void { this._capture('pause', null); }
+  finish(): void {
+    this._capture('finish', null);
+    this._onfinish();
+  }
+  set onfinish(fn: Function) {
+    this._capture('onfinish', fn);
+    this._onfinish = fn;
+  }
+  get onfinish(): Function { return this._onfinish; }
+  set position(val: number) {
+    this._capture('position', val);
+    this._position = val;
+  }
+  get position(): number { return this._position; }
+}