Reduce memory usage of ExtractZip by using python's zipfile.extractall
Reduce memory usage of ExtractZip by using python's zipfile.extractall

This may help with MemoryErrors on Windows bots during unpacking
1 GB+ files.

TBR=cmp

BUG=168411
Review URL: https://codereview.chromium.org/12114028

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@179875 0039d316-1c4b-4281-b951-d872f2087c98

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