Version 3.28.14 (based on bleeding_edge revision r22215)

Use the HeapObjectIterator to scan-on-scavenge map pages (Chromium issue 390732).

Introduce debug events for Microtask queue (Chromium issue 272416).

Split out libplatform into a separate libary.

Add clang-format to presubmit checks.

Stack traces exposed to Javascript should omit extensions (issue 311).

Remove deprecated v8::Context::HasOutOfMemoryException.

Postpone termination exceptions in debug scope (issue 3408).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@22220 ce2b1a6d-e550-0410-aec6-3dcde31c8c00