This patch replaces the unused 'take_snapshot' parameter on FatalProcessOutOfMemory()
with a 'is_heap_oom' parameter. The parameter is set to true on error paths where the
JS heap is out of memory, as distinct from a malloc() failure i.e. process out of memory.
The message output to stderr or passed to embedding applications via FatalErrorCallback
is 'Javascript heap out of memory' rather than 'process out of memory'.

BUG=

R=jochen@chromium.org, verwaest@chromium.org, michael_dawson@ca.ibm.com

Review URL: https://codereview.chromium.org/1873443002

Cr-Commit-Position: refs/heads/master@{#35431}