Add timeout for blink-revision-fetching code.
Add timeout for blink-revision-fetching code.

TBR=phadjan@chromium.org

Review URL: https://codereview.chromium.org/14980010

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@199561 0039d316-1c4b-4281-b951-d872f2087c98

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