Revert of Prepare browser_tests for data: urls being async

Revert of Prepare browser_tests for data: urls being async (https://codereview.chromium.org/257723002/)

Reason for revert:
This didn't fully solve the issue, no need to add the complexity.

Original issue's description:
> Prepare browser_tests for data: urls being async
> 
> RenderViewTest::LoadHTML assumed that issuing a load
> of a data url, posting a task to quit the message loop
> and then pumping the message loop until it quits was
> sufficient to end up with a fully parsed page.
> 
> That very soon won't be true once we send data: urls
> to the threaded parser, as the parser thread posts
> back to the main thread and may post tasks after the
> quit message.
> https://codereview.chromium.org/210253003/
> 
> Instead I've added a FrameLoadWaiter class which
> implements RenderViewObserver to listen for the
> load event for the frame and only post the quit
> task once the load event had come in.
> 
> BUG=308321
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266163

TBR=abarth@chromium.org,sky@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=308321
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266607

[eseidel, 2014-04-28 18:09:23]

Created Revert of Prepare browser_tests for data: urls being async

[commit-bot: I haz the power, 2014-04-28 18:10:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eseidel@chromium.org/252743006/1

[commit-bot: I haz the power, 2014-04-28 18:12:04]

Change committed as 266607