Re-land r93365 - add RefCountedString

base/base64.cc

Index: base/base64.cc
diff --git a/base/base64.cc b/base/base64.cc
index 56a577dbcf19b2dc6733a6657b8c77187ed00492..62bd12d1fb635f951f4ce7d2aa692cfb5a65aeab 100644
--- a/base/base64.cc
+++ b/base/base64.cc
@@ -8,7 +8,7 @@
 
 namespace base {
 
-bool Base64Encode(const std::string& input, std::string* output) {
+bool Base64Encode(const StringPiece& input, std::string* output) {
   std::string temp;
   temp.resize(modp_b64_encode_len(input.size()));  // makes room for null byte
 
@@ -23,7 +23,7 @@ bool Base64Encode(const std::string& input, std::string* output) {
   return true;
 }
 
-bool Base64Decode(const std::string& input, std::string* output) {
+bool Base64Decode(const StringPiece& input, std::string* output) {
   std::string temp;
   temp.resize(modp_b64_decode_len(input.size()));