Refactor fileutils.cc/h and fileutils_unittests.cc into their own targets.

webrtc/test/testsupport/fileutils.cc

Index: webrtc/test/testsupport/fileutils.cc
diff --git a/webrtc/test/testsupport/fileutils.cc b/webrtc/test/testsupport/fileutils.cc
index 97d58eba60f2835e348a0a9f8413ddb248a6ec69..c8054ba826eca7dee6b6c2228fb2d51f74912348 100644
--- a/webrtc/test/testsupport/fileutils.cc
+++ b/webrtc/test/testsupport/fileutils.cc
@@ -19,6 +19,7 @@
 #include <algorithm>
 
 #include "Shlwapi.h"
+#include "WinDef.h"
 
 #include "webrtc/system_wrappers/include/utf_util_win.h"
 #define GET_CURRENT_DIR _getcwd
@@ -135,7 +136,7 @@ std::string ProjectRootPath() {
   path = path + kPathDelimiter + ".." + kPathDelimiter + "..";
   char canonical_path[FILENAME_MAX];
 #ifdef WIN32
-  bool succeeded = PathCanonicalizeA(canonical_path, path.c_str());
+  BOOL succeeded = PathCanonicalizeA(canonical_path, path.c_str());
 #else
   bool succeeded = realpath(path.c_str(), canonical_path) != NULL;
 #endif