Revert 233703 "[sync] Re-enable TwoClientAppsSyncTest.Merge"

> [sync] Re-enable TwoClientAppsSyncTest.Merge
> 
> TwoClientAppsSyncTest.Merge was marked as flaky several months ago.
> Investigations have not yielded any obvious failure cause. The test
> passes with a large value for --gtest_repeat.
> 
> This patch re-enables the test assuming the trybots like it.
> 
> BUG=226055
> TEST=TwoClientAppsSyncTest.Merge
> R=pavely@chromium.org
> 
> Review URL: https://codereview.chromium.org/61763012

TBR=rsimha@chromium.org

Review URL: https://codereview.chromium.org/102043003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240130 0039d316-1c4b-4281-b951-d872f2087c98
linux_aura: Reenable most of the Extension tests.

BUG=316919, 163931
R=benwells@chromium.org

Review URL: https://codereview.chromium.org/99583003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240131 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240131