Revert 177666 "DevTools: Make the "common" module window- and DO..."

Reason of revert:
Broke ParseCapabilities.MobileEmulationDeviceName of chromedriver_unittests.
http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/builds/49752

I don't really understand how this patch causes the test to fail, but
local bisecting showed this patch was the culprit.

> DevTools: Make the "common" module window- and DOM-agnostic
> 
> This is required for the "common" module to be loadable in workers.
> 
> R=dgozman@chromium.org, pfeldman@chromium.org, aandrey, dgozman, vsevik
> BUG=391566
> 
> Review URL: https://codereview.chromium.org/371453004

TBR=apavlov@chromium.org

Review URL: https://codereview.chromium.org/379813002

git-svn-id: svn://svn.chromium.org/blink/trunk@177731 bbb929c8-8fbe-4397-9dbb-9b2b20218538