Fix deprecated V8 function use in GetOrCreateChromeObject

Fixes use of deprecated Object::Get/Set V8 functions in
content::GetOrCreateChromeObject by instead using the Context version
and checking the return values.

Bug: v8:7283, v8:8562
Change-Id: I16b147ec9f642a744b77516cf228fbd0a78f1bc3
Reviewed-on: https://chromium-review.googlesource.com/c/1447718
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#628372}
9 files changed