feat(ShadowCss): Support the new deep combinator syntax >>>

fixes angular#990

ref http://dev.w3.org/csswg/css-scoping-1/#deep-combinator

Closes angular#1028

Author: vicb

modules/angular2/src/core/compiler/shadow_dom_emulation/shadow_css.js

@@ -512,11 +512,13 @@ var _cssColonHostRe = RegExpWrapper.create('(' + _polyfillHost + _parenSuffix, '
 var _cssColonHostContextRe = RegExpWrapper.create('(' + _polyfillHostContext + _parenSuffix, 'im');
 var _polyfillHostNoCombinator = _polyfillHost + '-no-combinator';
 var _shadowDOMSelectorsRe = [
-  RegExpWrapper.create('/shadow/'),
-  RegExpWrapper.create('/shadow-deep/'),
+  RegExpWrapper.create('>>>'),
   RegExpWrapper.create('::shadow'),
-  RegExpWrapper.create('/deep/'),
   RegExpWrapper.create('::content'),
+  // Deprecated selectors
+  RegExpWrapper.create('/deep/'), // former >>>
+  RegExpWrapper.create('/shadow-deep/'), // former /deep/
+  RegExpWrapper.create('/shadow/'), // former ::shadow
 ];
 var _selectorReSuffix = '([>\\s~+\[.,{:][\\s\\S]*)?$';
 var _polyfillHostRe = RegExpWrapper.create(_polyfillHost, 'im');

modules/angular2/test/core/compiler/shadow_dom/shadow_css_spec.js

@@ -108,5 +108,10 @@ export function main() {
       var css = s('x /deep/ y {}', 'a');
       expect(css).toEqual('x[a] y[a] {}');
     });
+
+    it('should handle >>>', () => {
+      var css = s('x >>> y {}', 'a');
+      expect(css).toEqual('x[a] y[a] {}');
+    });
   });
 }