extensions: Use stl utilities from the base namespace

extensions/browser/computed_hashes.cc

Index: extensions/browser/computed_hashes.cc
diff --git a/extensions/browser/computed_hashes.cc b/extensions/browser/computed_hashes.cc
index dbfe00610997d41fb9a14e74ce73bdd0523472a9..bf0cf985a2867eb7aac582f5002087c50b797b41 100644
--- a/extensions/browser/computed_hashes.cc
+++ b/extensions/browser/computed_hashes.cc
@@ -184,7 +184,7 @@ void ComputedHashes::ComputeHashesForContent(const std::string& contents,
     hashes->push_back(std::string());
     std::string* buffer = &(hashes->back());
     buffer->resize(crypto::kSHA256Length);
-    hash->Finish(string_as_array(buffer), buffer->size());
+    hash->Finish(base::string_as_array(buffer), buffer->size());
 
     // If |contents| is empty, then we want to just exit here.
     if (bytes_to_read == 0)