Use native command for deleting a directory on Windows
Use native command for deleting a directory on Windows

TBR=tandrii@chromium.org
BUG=498256

Review URL: https://codereview.chromium.org/1329893003

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@296577 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build