Show squashed diffs in the diffviewer

Review Request #7135 — Created March 28, 2015 and submitted — Latest diff uploaded

Information

Review Board
dvcs
af9f908...

Reviewers

Previously we would show multiple FileDiffs for the same file in the
diff viewer if the file was modified in multiple commits. Now we
determine what FileDiffs are ancestors of other FileDiffs in the
commit history and filter out all the ancestors. The result is a
squashed diff between the original file and the resulting file.

Ran unit tests.

Manually verified that the squashed diffs were correct.

Still able to view the FileDiffs of review requests without
commit history.