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/class_linker.h b/src/class_linker.h
index 14c719e..e85a7f9 100644
--- a/src/class_linker.h
+++ b/src/class_linker.h
@@ -21,11 +21,11 @@
 #include <utility>
 #include <vector>
 
+#include "base/macros.h"
 #include "dex_cache.h"
 #include "dex_file.h"
 #include "gtest/gtest.h"
 #include "heap.h"
-#include "macros.h"
 #include "mutex.h"
 #include "oat_file.h"
 #include "object.h"