Oilpan: Add ALWAYS_INLINE to HeapObjectHeader::payloadSize
Oilpan: Add ALWAYS_INLINE to HeapObjectHeader::payloadSize

HeapObjectHeader::payloadSize is performance-sensitive since it's called
in tracing methods a lot of times. It looks like HeapObjectHeader::payloadSize
is already inlined in Linux so no binary size increase is observed in Linux.
Thus this is just an just-in-case CL.

BUG=420515

Review URL: https://codereview.chromium.org/973493002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@191202 bbb929c8-8fbe-4397-9dbb-9b2b20218538

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk