Revert 226305 "Fix code style and gyp files in cast to build cas..."

Seems to have broken win and mac:
http://build.chromium.org/p/chromium/builders/Win/builds/17341
http://build.chromium.org/p/chromium/builders/Mac/builds/22281

> Fix code style and gyp files in cast to build cast_unittest
> 
> *.gypi should not be used for dependency directly. Renaming those files
> to *.gyp. Also style fixes to make compilers happy.
> 
> This change is reland of r226264.
> 
> TBR=acolwell
> 
> Review URL: https://codereview.chromium.org/25544003

TBR=hclam@chromium.org

Review URL: https://codereview.chromium.org/25662002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226381 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226381