Now, using `ng.probe(element)` in the browser console returns
a DebugElement when in dev mode.
`ComponentFixture#debugElement` also returns a new DebugElement.
Breaking Change:
This is a breaking change for unit tests. The API for the DebugElement
has changed. Now, there is a DebugElement or DebugNode for every node
in the DOM, not only nodes with an ElementRef. `componentViewChildren` is
removed, and `childNodes` is a list of ElementNodes corresponding to every
child in the DOM. `query` no longer takes a scope parameter, since
the entire rendered DOM is included in the `childNodes`.
Before:
```
componentFixture.debugElement.componentViewChildren[0];
```
After
```
// Depending on the DOM structure of your component, the
// index may have changed or the first component child
// may be a sub-child.
componentFixture.debugElement.children[0];
```
Before:
```
debugElement.query(By.css('div'), Scope.all());
```
After:
```
debugElement.query(By.css('div'));
```
Before:
```
componentFixture.debugElement.elementRef;
```
After:
```
componentFixture.elementRef;
```