docs(testing): remove comments (#3483)

Author: Foxandxss

public/docs/ts/latest/guide/testing.jade

@@ -1681,18 +1681,13 @@ figure.image-display
   in `By.css('h2:not([highlight])')` helps find `<h2>` elements that _do not_ have the directive.
   `By.css('*:not([highlight])')` finds _any_ element that does not have the directive.
 
-// Removed on 12/02/2016 when ceased public discussion of the `Renderer`. Revive in future?
-:marked
   * `DebugElement.styles` affords access to element styles even in the absence of a real browser, thanks to the `DebugElement` abstraction.
   But feel free to exploit the `nativeElement` when that seems easier or more clear than the abstraction.
 
-:marked
   * Angular adds a directive to the injector of the element to which it is applied.
   The test for the default color uses the injector of the second `<h2>` to get its `HighlightDirective` instance
   and its `defaultColor`.
 
-// Removed on 12/02/2016 when ceased public discussion of the `Renderer`. Revive in future?
-:marked
   * `DebugElement.properties` affords access to the artificial custom property that is set by the directive.
 
 a(href="#top").to-top Back to top