Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/sync/test/integration/search_engines_helper.cc

Index: chrome/browser/sync/test/integration/search_engines_helper.cc
diff --git a/chrome/browser/sync/test/integration/search_engines_helper.cc b/chrome/browser/sync/test/integration/search_engines_helper.cc
index 5445d95129125c172f5c84691b99aa784b512701..2a1baa1ca76d348474997daa5fb76c385f41ffe6 100644
--- a/chrome/browser/sync/test/integration/search_engines_helper.cc
+++ b/chrome/browser/sync/test/integration/search_engines_helper.cc
@@ -108,7 +108,7 @@ bool ServicesMatch(int profile_a, int profile_b) {
 // Convenience helper for consistently generating the same keyword for a given
 // seed.
 base::string16 CreateKeyword(int seed) {
-  return ASCIIToUTF16(base::StringPrintf("test%d", seed));
+  return base::ASCIIToUTF16(base::StringPrintf("test%d", seed));
 }
 
 }  // namespace