Add SpdyString alias for std::string in net/spdy.

net/spdy/spdy_test_utils.cc

Index: net/spdy/spdy_test_utils.cc
diff --git a/net/spdy/spdy_test_utils.cc b/net/spdy/spdy_test_utils.cc
index f03e286d14e604b0201dab0b5e4add5639f507e0..100d84f014668876659d1511d1f003ef2f7e58e1 100644
--- a/net/spdy/spdy_test_utils.cc
+++ b/net/spdy/spdy_test_utils.cc
@@ -22,12 +22,10 @@
 namespace net {
 namespace test {
 
-using std::string;
-
-string HexDumpWithMarks(const unsigned char* data,
-                        int length,
-                        const bool* marks,
-                        int mark_length) {
+SpdyString HexDumpWithMarks(const unsigned char* data,
+                            int length,
+                            const bool* marks,
+                            int mark_length) {
   static const char kHexChars[] = "0123456789abcdef";
   static const int kColumns = 4;
 
@@ -38,7 +36,7 @@ string HexDumpWithMarks(const unsigned char* data,
     mark_length = std::min(mark_length, kSizeLimit);
   }
 
-  string hex;
+  SpdyString hex;
   for (const unsigned char* row = data; length > 0;
        row += kColumns, length -= kColumns) {
     for (const unsigned char *p = row; p < row + 4; ++p) {
@@ -64,7 +62,7 @@ string HexDumpWithMarks(const unsigned char* data,
   return hex;
 }
 
-void CompareCharArraysWithHexError(const string& description,
+void CompareCharArraysWithHexError(const SpdyString& description,
                                    const unsigned char* actual,
                                    const int actual_len,
                                    const unsigned char* expected,
@@ -106,9 +104,9 @@ void SetFrameLength(SpdySerializedFrame* frame, size_t length) {
   }
 }
 
-string a2b_hex(const char* hex_data) {
+SpdyString a2b_hex(const char* hex_data) {
   std::vector<uint8_t> output;
-  string result;
+  SpdyString result;
   if (base::HexStringToBytes(hex_data, &output))
     result.assign(reinterpret_cast<const char*>(&output[0]), output.size());
   return result;
@@ -120,23 +118,23 @@ HashValue GetTestHashValue(uint8_t label) {
   return hash_value;
 }
 
-string GetTestPin(uint8_t label) {
+SpdyString GetTestPin(uint8_t label) {
   HashValue hash_value = GetTestHashValue(label);
-  string base64;
+  SpdyString base64;
   base::Base64Encode(SpdyStringPiece(reinterpret_cast<char*>(hash_value.data()),
                                      hash_value.size()),
                      &base64);
 
-  return string("pin-sha256=\"") + base64 + "\"";
+  return SpdyString("pin-sha256=\"") + base64 + "\"";
 }
 
 void AddPin(TransportSecurityState* state,
-            const string& host,
+            const SpdyString& host,
             uint8_t primary_label,
             uint8_t backup_label) {
-  string primary_pin = GetTestPin(primary_label);
-  string backup_pin = GetTestPin(backup_label);
-  string header = "max-age = 10000; " + primary_pin + "; " + backup_pin;
+  SpdyString primary_pin = GetTestPin(primary_label);
+  SpdyString backup_pin = GetTestPin(backup_label);
+  SpdyString header = "max-age = 10000; " + primary_pin + "; " + backup_pin;
 
   // Construct a fake SSLInfo that will pass AddHPKPHeader's checks.
   SSLInfo ssl_info;