adb/base win32 tests: fix comment and open() flags

Match base's use of O_BINARY.

Change-Id: I930b5c8fddde20966580069f2e681b99cb26f1a3
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>

adb/adb_io_test.cpp

@@ -31,10 +31,11 @@
 #include "base/test_utils.h"
 
 // All of these tests fail on Windows because they use the C Runtime open(),
-// but the adb_io APIs expect file descriptors from adb_open(). Also, the
-// android::base file APIs use the C Runtime which uses CR/LF translation by
-// default (changeable with _setmode()), but the adb_io APIs use adb_read()
-// and adb_write() which do no translation.
+// but the adb_io APIs expect file descriptors from adb_open(). This could
+// theoretically be fixed by making adb_read()/adb_write() fallback to using
+// read()/write() if an unrecognized fd is used, and by making adb_open() return
+// fds far from the range that open() returns. But all of that might defeat the
+// purpose of the tests.
 
 TEST(io, ReadFdExactly_whole) {
   const char expected[] = "Foobar";

base/test_utils.cpp

@@ -37,9 +37,9 @@ int mkstemp(char* template_name) {
     return -1;
   }
   // Use open() to match the close() that TemporaryFile's destructor does.
-  // Note that on Windows, this does CR/LF translation and _setmode() should
-  // be used to change that if appropriate.
-  return open(template_name, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR);
+  // Use O_BINARY to match base file APIs.
+  return open(template_name, O_CREAT | O_EXCL | O_RDWR | O_BINARY,
+              S_IRUSR | S_IWUSR);
 }
 
 char* mkdtemp(char* template_name) {