Switch over to the google3 unix_file File*.

I also moved macros.h to base/macros.h to ease google3 porting, at
the expense of a larger than necessary change. (I learned my lesson,
though, and didn't make the equivalent base/logging.h change.)

I'm not sure whether we want to keep the unix_file MappedFile given
our existing MemMap, but it's easier to bring it over and then remove
it (and possibly revert the removal) than to bring it over later.

Change-Id: Id50a66faa5ab17b9bc936cc9043dbc26f791f0ca
diff --git a/src/indenter.h b/src/indenter.h
index f66df08..4ac0c01 100644
--- a/src/indenter.h
+++ b/src/indenter.h
@@ -17,7 +17,7 @@
 #ifndef ART_SRC_INDENTER_H_
 #define ART_SRC_INDENTER_H_
 
-#include "macros.h"
+#include "base/macros.h"
 #include <streambuf>
 
 const char kIndentChar =' ';