Move PathExists to base namespace.

chromeos/system/name_value_pairs_parser.cc

Index: chromeos/system/name_value_pairs_parser.cc
diff --git a/chromeos/system/name_value_pairs_parser.cc b/chromeos/system/name_value_pairs_parser.cc
index e537c0de3ed4c5b1934b0ae22695067d1a212d57..d4765202573c473ac3123e6c730f25e2bbd0cb61 100644
--- a/chromeos/system/name_value_pairs_parser.cc
+++ b/chromeos/system/name_value_pairs_parser.cc
@@ -24,7 +24,7 @@ const char kTrimChars[] = "\" ";
 bool GetToolOutput(int argc, const char* argv[], std::string& output) {
   DCHECK_GE(argc, 1);
 
-  if (!file_util::PathExists(base::FilePath(argv[0]))) {
+  if (!base::PathExists(base::FilePath(argv[0]))) {
     LOG(WARNING) << "Tool for statistics not found: " << argv[0];
     return false;
   }