Changing Size to SizeOfObjects in GetHeapSpaceStatistics api.
Changing Size to SizeOfObjects in GetHeapSpaceStatistics api.

This CL changes GetHeapSpaceStatistics api to return SizeOfObjects()
instead of Size(). SizeOfObjects is the required field and is
consistent with GetHeapStatistics api.

BUG=476013
LOG=N

Review URL: https://codereview.chromium.org/1095393005

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28080}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh