Add utf_string_conversions to base namespace.

chrome/installer/util/move_tree_work_item_unittest.cc

Index: chrome/installer/util/move_tree_work_item_unittest.cc
diff --git a/chrome/installer/util/move_tree_work_item_unittest.cc b/chrome/installer/util/move_tree_work_item_unittest.cc
index bead46ebfc1cc517dfde18aee867746b3fb42e01..7a1900727d3847fa8067a3763786ddaba6d56e6b 100644
--- a/chrome/installer/util/move_tree_work_item_unittest.cc
+++ b/chrome/installer/util/move_tree_work_item_unittest.cc
@@ -33,7 +33,7 @@ class MoveTreeWorkItemTest : public testing::Test {
 void CreateTextFile(const std::wstring& filename,
                     const std::wstring& contents) {
   std::wofstream file;
-  file.open(WideToASCII(filename).c_str());
+  file.open(base::WideToASCII(filename).c_str());
   ASSERT_TRUE(file.is_open());
   file << contents;
   file.close();
@@ -43,7 +43,7 @@ void CreateTextFile(const std::wstring& filename,
 std::wstring ReadTextFile(const base::FilePath& path) {
   WCHAR contents[64];
   std::wifstream file;
-  file.open(WideToASCII(path.value()).c_str());
+  file.open(base::WideToASCII(path.value()).c_str());
   EXPECT_TRUE(file.is_open());
   file.getline(contents, arraysize(contents));
   file.close();