Classes: Cleanup default constructor flag

Classes: Cleanup default constructor flag

Now that we keep track of whether a function contains super we do not
need kDefaultConstructorCallSuper

BUG=None
LOG=Y
R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/718833002

Cr-Commit-Position: refs/heads/master@{#25337}