I've worked with the team that built it, so I can verify that ASAN is definitely a Google project. Also, some other people have posted comments to links that verify the association.
As for the electric fence comparison, ASANs strengths are that it provides more detailed reports and detects more types of errors, but is still very fast. For example, ASAN will detect stack and global boundary violations, whereas electric fence will not.
As for the electric fence comparison, ASANs strengths are that it provides more detailed reports and detects more types of errors, but is still very fast. For example, ASAN will detect stack and global boundary violations, whereas electric fence will not.