Modify SincResampler to build in webrtc.

This is the first in a series of CLs to bring arbitrary resampling to webrtc.

* Replace Chromium-specific helpers with their respective webrtc versions.
* Add a second constructor to permit runtime selection of block_size.
* Add stringize_macros to system_wrappers.

BUG=webrtc:1395
TESTED=unit tests

Review URL: https://webrtc-codereview.appspot.com/1097012

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3518 4adac7df-926f-26a2-2b94-8c16560cd09d
7 files changed