Revert 167360 "Revert 167276 "Remove isolatedWorldForEnteredCont..."

> Revert 167276 "Remove isolatedWorldForEnteredContext() and isola..."
> 
> > Remove isolatedWorldForEnteredContext() and isolatedWorldForIsolate()
> > 
> > - isolatedWorldForIsolate() is equivalent to DOMWrapperWorld::current()->isIsolatedWorld().
> > 
> > - isolatedWorldForEnteredContext() is equivalent to DOMWrapperWorld::current()->isIsolatedWorld(). Remember that the world of the current context is equal to the world of the entered context.
> > 
> > Thus this CL replaces these methods with DOMWrapperWorld::current()->isIsolatedWorld().
> > 
> > BUG=341032
> > R=dcarney@chromium.org, eseidel@chromium.org
> > 
> > Review URL: https://codereview.chromium.org/137953010
> 
> TBR=haraken@chromium.org
> 
> Review URL: https://codereview.chromium.org/170893003

TBR=alecflett@chromium.org

Review URL: https://codereview.chromium.org/171313003

git-svn-id: svn://svn.chromium.org/blink/trunk@167361 bbb929c8-8fbe-4397-9dbb-9b2b20218538