Revert 192940 "Delete CopyRecursiveDirNoCache from test_file_util."

Revert 192940 "Delete CopyRecursiveDirNoCache from test_file_util."

Likely culprit for startup test crashes on mac.

BUG=229665
> Delete CopyRecursiveDirNoCache from test_file_util.
> 
> This function was used in only one place and that place was wrong.
> 
> The implementation was long and complicated on Windows, and long and
> complicated and copied verbatim from elsewhere with 3 lines different on Posix.
> 
> The place it was used was in the proxy launcher when copying the profile. It's
> not clear to me why we wouldn't want the profile files in the filesystem cache
> when running tests. Quite the opposite, we want the tests to run as fast as
> possible.
> 
> The only place this should matter is in the startup tests. And the startup
> tests do things to the profile after it gets copied that should page some files
> back in! This adds another step to the startup tests to evict the profile files
> for cold startup tests only.
> 
> This is a reland of r191854 which broke the startup test. The previous patch replaced the CopyRecursive call with CopyDirectory which does something slightly different. This new patch implements a CopyDirectoryContents function to do what's required here.
> 
> patch from issue 13394003
> 
> Review URL: https://codereview.chromium.org/13646016

TBR=brettw@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193253

[tonyg, 2013-04-09 23:05:48]

Committed patchset #1 manually as r193253.