Added methods to enable configuration of ResourceConstraints based on limits derived at runtime. (Chromium issue 292928)

Added -optimize-for-size flag to optimize for memory size (will be used by pre-aging CL), and removed the is_memory_constrained ResourceConstraint. (Chromium issue 292928)

Performance and stability improvements on all platforms.

git-svn-id: http://v8.googlecode.com/svn/trunk@16974 ce2b1a6d-e550-0410-aec6-3dcde31c8c00