1.) The header is now in base/mac instead of base/memory
2.) The class is now in namespace base.

This CL was created programmatically by running:

1.)
    git grep -l memory/scoped_nsobject.h | xargs sed -i -e 's/memory\/scoped_nsobject.h/mac\/scoped_nsobject.h/g'
    for f in $(git diff --name-only origin); do tools/sort-headers.py $f -f; done
    git commit -a -m headers
    # manually undo changes to gypi file
    git cl upload # patch set 1
2.)
    git grep -l 'scoped_nsobject<' | xargs sed -i -e 's/scoped_nsobject</base::scoped_nsobject</g'
    # manually undo comment changes in scoped_nsobject.h, tracking_area.h
    git commit -a -m format
    git cl upload # patch set 2
    # Manually audit all files, file bugs and clean up bad clang-format decisions
    git cl upload # patch set 3
BUG=251957
TBR=mark@chromium.org

Review URL: https://codereview.chromium.org/17593006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@208283 0039d316-1c4b-4281-b951-d872f2087c98