Revert "Fix flakiness in AutomationApiTest.DesktopHitTestIframe"

This reverts commit 2c1a16509753dfce11564e5c37ffe8a134a2b3dc.

Reason for revert: This is still flaking.

Original change's description:
> Fix flakiness in AutomationApiTest.DesktopHitTestIframe
> 
> At least one issue was that the loadComplete event was sometimes being
> received on a frame with an empty url.
> 
> Bug: 808343,622387
> Change-Id: I7040a75c91f409ba07d3b9ad4e4598805e94b6ce
> Reviewed-on: https://chromium-review.googlesource.com/938495
> Reviewed-by: David Tseng <dtseng@chromium.org>
> Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#540097}

TBR=dmazzoni@chromium.org,dtseng@chromium.org

Change-Id: If3a4f36c64d2a2d2be04d7d520082344edcc1290
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 808343, 622387
Reviewed-on: https://chromium-review.googlesource.com/944768
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540356}
3 files changed