Revert of Try waiting for image load in flaky svg test (https://codereview.chromium.org/292983008/)

Reason for revert:
This experiment was unsuccessful.  Test is still flaky.

Original issue's description:
> Try waiting for image load in flaky svg test
> 
> It's not clear to me why these tests are flaking, but one possibility is
> that there's a race with the image loading and layout.  This is a test
> to wait for the repaint test until the image has loaded.
> 
> R=pdr@chromium.org
> BUG=374936
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=174438

TBR=pdr@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=374936

Review URL: https://codereview.chromium.org/295103004

git-svn-id: svn://svn.chromium.org/blink/trunk@174460 bbb929c8-8fbe-4397-9dbb-9b2b20218538