Add utf_string_conversions to base namespace.

chrome/installer/util/install_util.cc

Index: chrome/installer/util/install_util.cc
diff --git a/chrome/installer/util/install_util.cc b/chrome/installer/util/install_util.cc
index 0c02d71abcb49dc7cb64e720c4f64188250cafa2..3ba49550d91ababc597abd4ac558c2f387084c2d 100644
--- a/chrome/installer/util/install_util.cc
+++ b/chrome/installer/util/install_util.cc
@@ -225,7 +225,7 @@ void InstallUtil::GetChromeVersion(BrowserDistribution* dist,
   if (result == ERROR_SUCCESS && !version_str.empty()) {
     VLOG(1) << "Existing " << dist->GetAppShortCutName() << " version found "
             << version_str;
-    *version = Version(WideToASCII(version_str));
+    *version = Version(base::WideToASCII(version_str));
   } else {
     DCHECK_EQ(ERROR_FILE_NOT_FOUND, result);
     VLOG(1) << "No existing " << dist->GetAppShortCutName()
@@ -251,7 +251,7 @@ void InstallUtil::GetCriticalUpdateVersion(BrowserDistribution* dist,
   if (result == ERROR_SUCCESS && !version_str.empty()) {
     VLOG(1) << "Critical Update version for " << dist->GetAppShortCutName()
             << " found " << version_str;
-    *version = Version(WideToASCII(version_str));
+    *version = Version(base::WideToASCII(version_str));
   } else {
     DCHECK_EQ(ERROR_FILE_NOT_FOUND, result);
     VLOG(1) << "No existing " << dist->GetAppShortCutName()