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

chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc

Index: chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc
diff --git a/chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc b/chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc
index 5a8badee8ad8f0eb1eb4087f75edc63cf125e38f..9463ebe239920397a65912187d00de6441cfc077 100644
--- a/chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc
+++ b/chrome/browser/ui/blocked_content/popup_blocker_browsertest.cc
@@ -332,7 +332,8 @@ IN_PROC_BROWSER_TEST_F(PopupBlockerBrowserTest,
   ui_test_utils::SendToOmniboxAndSubmit(location_bar, search_string);
   OmniboxEditModel* model = location_bar->GetOmniboxView()->model();
   EXPECT_EQ(GURL(search_string), model->CurrentMatch(NULL).destination_url);
-  EXPECT_EQ(ASCIIToUTF16(search_string), model->CurrentMatch(NULL).contents);
+  EXPECT_EQ(base::ASCIIToUTF16(search_string),
+            model->CurrentMatch(NULL).contents);
 }
 
 // This test fails on linux AURA with this change