Revert 251090 "Revert 250823 "With --site-per-process, avoid a c..."

Relanding, this wasn't the cause of the failures.

> Revert 250823 "With --site-per-process, avoid a crash when a sub..."
> 
> Speculative revert to see if the navigation changes here are causing
> sync_integration_tests to fail on:
> 
> http://build.chromium.org/p/chromium.win/builders/Win7%20Sync%20x64/builds/11217
> 
> > With --site-per-process, avoid a crash when a subframe process goes away.
> > 
> > We need to clear out the children of any nodes that are affected by the
> > crash, not the entire FrameTree.
> > 
> > BUG=338508
> > TEST=Killing an iframe process with --site-per-process shows a green rectangle.
> > R=ajwong@chromium.org, nasko@chromium.org
> > 
> > Review URL: https://codereview.chromium.org/156303004
> 
> TBR=creis@chromium.org
> 
> Review URL: https://codereview.chromium.org/163703004

TBR=asvitkine@chromium.org

Review URL: https://codereview.chromium.org/163183005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251110 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251110
Rename ServiceConnector back to ServiceManager

BUG=None
TEST=None
TBR=darin

Review URL: https://codereview.chromium.org/164313002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251111 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251111