Revert "Revert "adb/base: fix adb push of Unicode filenames on Win32""

This reverts commit cc8cd59456ca485a51cd6fd388c8bcb1af4a8f9b.

With the dependency on libcutils (for gettid for non-bionic) removed,
this no longer breaks the build.

Change-Id: I645bd6876e2502ddc1535b69af1e645c0df9d178
diff --git a/base/file.cpp b/base/file.cpp
index 3468dcf..7b5e7b1 100644
--- a/base/file.cpp
+++ b/base/file.cpp
@@ -24,6 +24,7 @@
 #include <string>
 
 #include "base/macros.h"  // For TEMP_FAILURE_RETRY on Darwin.
+#include "base/utf8.h"
 #define LOG_TAG "base.file"
 #include "cutils/log.h"
 #include "utils/Compat.h"
@@ -35,6 +36,9 @@
 namespace android {
 namespace base {
 
+// Versions of standard library APIs that support UTF-8 strings.
+using namespace android::base::utf8;
+
 bool ReadFdToString(int fd, std::string* content) {
   content->clear();