Current state and proposed changes for blackboxing: https://docs.google.com/document/d/1hnzaXPAN8_QC5ENxIgxgMNDbXLraM_OXT73rAyijTF8/edit?usp=sharing

BUG=v8:5842,chromium:583193
R=yangguo@chromium.org,dgozman@chromium.org,alph@chromium.org

Review-Url: https://codereview.chromium.org/2648353006
Cr-Commit-Position: refs/heads/master@{#42668}