Make bisect script to post build request job to try server.

During the course of bisect, if the script don't find build archive for a given revision on cloud storage, a request is made to try server to produce one and waits till build archive is created on storage.

Note: In this CL, only chromium revision are taken care. I'll create a separate CL for third-party repositories such as v8, webkit.

Review URL: https://codereview.chromium.org/184293011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256862 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256862
Move more file_util functions to base namespace.

TBR=jam

Review URL: https://codereview.chromium.org/189333004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256863 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256863