Revert 230720 "DevTools: Introduce DevToolsTargetImpl to unify d..."

> DevTools: Introduce DevToolsTargetImpl to unify debug target across several places in Chrome
> 
> R=vsevik@chromium.org
> TBR=jochen@chromium.org for chrome.gyp
> BUG=None
> 
> Review URL: https://codereview.chromium.org/27217005

TBR=kaznacheev@chromium.org

Review URL: https://codereview.chromium.org/40633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230743 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230743