implemented CSS animations

fixing animation tests

ui/page/page-common.ts

@@ -8,6 +8,7 @@ import * as style from "../styling/style";
 import * as fileSystemModule from "file-system";
 import * as frameModule from "ui/frame";
 import proxy = require("ui/core/proxy");
+import keyframeAnimation = require("ui/animation/keyframe-animation");
 
 var fs: typeof fileSystemModule;
 function ensureFS() {
@@ -175,6 +176,15 @@ export class Page extends ContentView implements dts.Page {
         }
     }
 
+    public removeCssSelectors(selectorExpression: string) {
+        this._styleScope.removeSelectors(selectorExpression);
+        this._refreshCss();
+    }
+
+    public getKeyframeAnimationWithName(animationName: string): keyframeAnimation.KeyframeAnimationInfo {
+        return this._styleScope.getKeyframeAnimationWithName(animationName);
+    }
+
     get frame(): frameModule.Frame {
         return <frameModule.Frame>this.parent;
     }

ui/page/page.d.ts

@@ -8,6 +8,7 @@ declare module "ui/page" {
     import frame = require("ui/frame");
     import actionBar = require("ui/action-bar");
     import dependencyObservable = require("ui/core/dependency-observable");
+    import keyframeAnimation = require("ui/animation/keyframe-animation");
 
     //@private
     import styleScope = require("ui/styling/style-scope");
@@ -120,6 +121,17 @@ declare module "ui/page" {
          */
         addCssFile(cssFileName: string): void;
 
+        /**
+         * Removes all selectors matching the specified selector expression.
+         * @param selectorExpression - A valid selector expression.
+         */
+        removeCssSelectors(selectorExpression: string): void;
+
+        /**
+         * Returns a CSS keyframe animation with the specified name, if it exists.
+         */
+        getKeyframeAnimationWithName(animationName: string): keyframeAnimation.KeyframeAnimationInfo;
+
         /**
          * A property that is used to pass a data from another page (while navigate to).
          */