Remove global std::strings from fileutils.

This is forbidden by the style guide and can cause the static
initialization order fiasco.

BUG=
TEST=test_support_unittests

Review URL: http://webrtc-codereview.appspot.com/248006

git-svn-id: http://webrtc.googlecode.com/svn/trunk@846 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/test/testsupport/fileutils.cc b/test/testsupport/fileutils.cc
index cc35772..098dad7 100644
--- a/test/testsupport/fileutils.cc
+++ b/test/testsupport/fileutils.cc
@@ -25,7 +25,11 @@
 namespace webrtc {
 namespace test {
 
-const std::string GetProjectRootPath() {
+// The file we're looking for to identify the project root dir.
+static const char* kProjectRootFileName = "DEPS";
+const char* kCannotFindProjectRootDir = "ERROR_CANNOT_FIND_PROJECT_ROOT_DIR";
+
+std::string GetProjectRootPath() {
   char path_buffer[FILENAME_MAX];
   if (!GET_CURRENT_DIR(path_buffer, sizeof(path_buffer))) {
     fprintf(stderr, "Cannot get current directory!\n");