Version 4.2.50 (based on 8c652127)

Reset inlining limits due to overly long compilation times in Speedometer, Dart2JS (Chromium issue 454625).

Add WeakMap to v8.h (Chromium issue 437416).

[V8] Added line, column and script symbols for SyntaxError (Chromium issue 443140).

Performance and stability improvements on all platforms.

Cr-Commit-Position: refs/heads/candidates@{#25437}