scoped_refptr implicit conversion cleanup tool.

Adapted from rsleevi's original patch. The initial version of the tool rewrites
all implicit conversions of scoped_refptr<T> to T*, even unsafe ones where a
temporary scoped_refptr<T> is assigned to a T*. A small tweak/hack has also
been added to run_tool.py to allow it to handle replacements that contain
embedded newlines.

BUG=110610
R=mdempsky@chromium.org, thakis@chromium.org

Review URL: https://codereview.chromium.org/446203003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288163 0039d316-1c4b-4281-b951-d872f2087c98
29 files changed