extensions: Use stl utilities from the base namespace

extensions/browser/content_hash_tree_unittest.cc

Index: extensions/browser/content_hash_tree_unittest.cc
diff --git a/extensions/browser/content_hash_tree_unittest.cc b/extensions/browser/content_hash_tree_unittest.cc
index 6d35dd55b8c135429b1dcde356d3d622ab07a753..f9be82eb8b85c718e1598a22d51da43babaf5644 100644
--- a/extensions/browser/content_hash_tree_unittest.cc
+++ b/extensions/browser/content_hash_tree_unittest.cc
@@ -43,7 +43,7 @@ TEST(ContentHashTreeTest, HashTreeBasics) {
   std::unique_ptr<SecureHash> hash(SecureHash::Create(SecureHash::SHA256));
   hash->Update(node1.data(), node1.size());
   hash->Update(node2.data(), node2.size());
-  hash->Finish(string_as_array(&expected), expected.size());
+  hash->Finish(base::string_as_array(&expected), expected.size());
   EXPECT_EQ(expected, ComputeTreeHashRoot(nodes, 16));
 }