Move PathExists to base namespace.

chrome/installer/util/copy_tree_work_item.cc

Index: chrome/installer/util/copy_tree_work_item.cc
diff --git a/chrome/installer/util/copy_tree_work_item.cc b/chrome/installer/util/copy_tree_work_item.cc
index ea14ea1647a1a68ac5fd43c067c0c2f373572231..6f44e5918a3cc3906fb13bf5ed102bac15db6e7b 100644
--- a/chrome/installer/util/copy_tree_work_item.cc
+++ b/chrome/installer/util/copy_tree_work_item.cc
@@ -29,12 +29,12 @@ CopyTreeWorkItem::CopyTreeWorkItem(const base::FilePath& source_path,
 }
 
 bool CopyTreeWorkItem::Do() {
-  if (!file_util::PathExists(source_path_)) {
+  if (!base::PathExists(source_path_)) {
     LOG(ERROR) << source_path_.value() << " does not exist";
     return false;
   }
 
-  bool dest_exist = file_util::PathExists(dest_path_);
+  bool dest_exist = base::PathExists(dest_path_);
   // handle overwrite_option_ = IF_DIFFERENT case.
   if ((dest_exist) &&
       (overwrite_option_ == WorkItem::IF_DIFFERENT) &&  // only for single file
@@ -52,7 +52,7 @@ bool CopyTreeWorkItem::Do() {
              (IsFileInUse(dest_path_))) {
     // handle overwrite_option_ = NEW_NAME_IF_IN_USE case.
     if (alternative_path_.empty() ||
-        file_util::PathExists(alternative_path_) ||
+        base::PathExists(alternative_path_) ||
         !base::CopyFile(source_path_, alternative_path_)) {
       LOG(ERROR) << "failed to copy " << source_path_.value()
                  << " to " << alternative_path_.value();
@@ -126,7 +126,7 @@ void CopyTreeWorkItem::Rollback() {
 }
 
 bool CopyTreeWorkItem::IsFileInUse(const base::FilePath& path) {
-  if (!file_util::PathExists(path))
+  if (!base::PathExists(path))
     return false;
 
   HANDLE handle = ::CreateFile(path.value().c_str(), FILE_ALL_ACCESS,