Ideally inliner itself should not deal with context specialization at
all, since this is all handled in the pipeline instead (actually
inlining already runs together with context specialization), and the
inlining logic should not care about the specialization mode.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1217973003

Cr-Commit-Position: refs/heads/master@{#29366}