Add utf_string_conversions to base namespace.

chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc

Index: chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc
diff --git a/chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc b/chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc
index 4a26fca5118a42c91fd948a1fb4b57bd19427691..3c1209c2ed226b9c5d16d62c8cb38c3015acf4b7 100644
--- a/chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc
+++ b/chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc
@@ -109,8 +109,8 @@ TEST_F(SpellCheckProviderTest, CancelUnnecessaryRequests) {
   // Test that the SpellCheckProvider class sends a request when it receives a
   // Russian word.
   const wchar_t kRussianWord[] = L"\x0431\x0451\x0434\x0440\x0430";
-  provider_.RequestTextChecking(WebKit::WebString(WideToUTF16(kRussianWord)),
-                                &completion);
+  provider_.RequestTextChecking(WebKit::WebString(
+      base::WideToUTF16(kRussianWord)), &completion);
   EXPECT_EQ(completion.completion_count_, 4U);
   EXPECT_EQ(completion.cancellation_count_, 2U);
 }