Revert of DevTools: cleanup treeoutline expand logic (patchset #1 id:1 of https://codereview.chromium.org/2147343002/ )

Reason for revert:
[Devtools] Broke header tabs in network tab

BUG=630971
Original issue's description:
> DevTools: cleanup treeoutline expand logic
>
> TreeElement.expand() should not need to check that the element has children and
> TreeOutline.insertChild() should not automatically expand a child when it is
> inserted. ObjectPropertiesSection.js depended on this logic to automatically
> expand the Entries property. This CL updates it so that the Entries property is
> added before expanded.
>
> BUG=
>
> Committed: https://crrev.com/cf5b729f072ba670c7b9966407fb3d47eb2169e7
> Cr-Commit-Position: refs/heads/master@{#407061}

TBR=lushnikov@chromium.org,luoe@chromium.org

Review-Url: https://codereview.chromium.org/2182783002
Cr-Commit-Position: refs/heads/master@{#407801}
2 files changed