Revert r170536 - "Rename DatabaseTaskSynchronizer to TaskSynchronizer ..."

This is a speculative revert to see if causes the WebKit Android N4 bot
to stop crashing.

TBR=haraken@chromium.org, rafaelw@chromium.org, tkent@chromium.org
BUG=

Review URL: https://codereview.chromium.org/219963019

git-svn-id: svn://svn.chromium.org/blink/trunk@170616 bbb929c8-8fbe-4397-9dbb-9b2b20218538
This test times out on other platforms too

TBR=dpranke@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/219963018

git-svn-id: svn://svn.chromium.org/blink/trunk@170617 bbb929c8-8fbe-4397-9dbb-9b2b20218538