Edit precompile to eliminate headers that define 'interface'.

Eliminate headers from precompile.h that define 'interface' to avoid compile failures on Windows that would not be seen on Mac or Linux.  I didn't do an exact measurement but I think we lose very little in terms of build time from this; Windows.h is the big Windows-specific header and it's still precompiled.

BUG=none
TEST=it builds

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=101059

[Jói, 2011-09-13 23:09:56]

Brett, I renamed gl_interface in one file back (vs. http://crrev.com/99949) to
just 'interface' as this renaming was the least beautiful one in my opinion, and
to check if my fix avoids problems with using 'interface' as a variable name.  I
left several other files where I had renamed variables alone, just to avoid
churn, and because I don't think the renaming there caused any loss of code
beauty.  Let me know if you think otherwise.

Cheers,
Jói

[brettw, 2011-09-13 23:37:53]

That's fine. LGTM, sorry this is so much work.