Revert r5520

Unfortunately, since we can only build ANGLE by including a gypi, and since
gyp cannot process includes conditionally, we *have* to have a build_angle.gypi
file in the third_party/externals/ANGLE/src directory.  We could do a hack
where we create an empty gypi if ANGLE is not checked out, but for now we just
check out ANGLE on all platforms.

git-svn-id: http://skia.googlecode.com/svn/trunk@5521 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed