Version 4.3.61.20 (cherry-pick)

Merged f6d632bd

Reduce the size of initial JSON string buffer.

BUG=v8:3925,chromium:403113
LOG=N
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1139713002

Cr-Commit-Position: refs/branch-heads/4.3@{#23}
Cr-Branched-From: f5c0a23a-refs/heads/4.3.61@{#1}
Cr-Branched-From: 0a7d4f49-refs/heads/master@{#27508}