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/zip_archive_test.cc b/src/zip_archive_test.cc
index 7409ec4..9bdc24b 100644
--- a/src/zip_archive_test.cc
+++ b/src/zip_archive_test.cc
@@ -36,11 +36,11 @@
 
   ScratchFile tmp;
   ASSERT_NE(-1, tmp.GetFd());
-  UniquePtr<File> file(OS::FileFromFd(tmp.GetFilename().c_str(), tmp.GetFd()));
+  UniquePtr<File> file(new File(tmp.GetFd(), tmp.GetFilename()));
   ASSERT_TRUE(file.get() != NULL);
   bool success = zip_entry->ExtractToFile(*file);
   ASSERT_TRUE(success);
-  close(tmp.GetFd());
+  file.reset(NULL);
 
   uint32_t computed_crc = crc32(0L, Z_NULL, 0);
   int fd = open(tmp.GetFilename().c_str(), O_RDONLY);