Port r152639 and r177025 to tracing_ and devtools_resources.gyp.

Gets rid of two msvs_cygwin_shell=1.

Also remove a bunch of msvs_cygwin_shell=0s -- this is now the default and
doesn't have to be set explicitly any more.

BUG=123026
R=cpu@chromium.org
TBR=jam

Review URL: https://codereview.chromium.org/140493003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245798 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245798