align clangcl using declspec instead of gcc style vector BUG=451 TESTED=clang=1 build on windows R=harryjin@google.com
align clangcl using declspec instead of gcc style vector
BUG=451
TESTED=clang=1 build on windows
R=harryjin@google.com

Review URL: https://webrtc-codereview.appspot.com/57549004
tony2012/libyuv,tony2012/libyuv,tony2012/libyuv