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

net/spdy/spdy_test_utils.h

Index: net/spdy/spdy_test_utils.h
diff --git a/net/spdy/spdy_test_utils.h b/net/spdy/spdy_test_utils.h
index feb307d48be91e1f2f9e348c74e3674c54196fbf..2bd20499a5fb920aa27bd35eecf01328325b04ff 100644
--- a/net/spdy/spdy_test_utils.h
+++ b/net/spdy/spdy_test_utils.h
@@ -8,8 +8,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include <string>
-
+#include "net/spdy/platform/api/spdy_string.h"
 #include "net/spdy/platform/api/spdy_string_piece.h"
 #include "net/spdy/server_push_delegate.h"
 #include "net/spdy/spdy_bug_tracker.h"
@@ -32,32 +31,33 @@ inline bool operator==(SpdyStringPiece x,
 
 namespace test {
 
-std::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);
 
-void CompareCharArraysWithHexError(
-    const std::string& description,
-    const unsigned char* actual,
-    const int actual_len,
-    const unsigned char* expected,
-    const int expected_len);
+void CompareCharArraysWithHexError(const SpdyString& description,
+                                   const unsigned char* actual,
+                                   const int actual_len,
+                                   const unsigned char* expected,
+                                   const int expected_len);
 
 void SetFrameFlags(SpdySerializedFrame* frame, uint8_t flags);
 
 void SetFrameLength(SpdySerializedFrame* frame, size_t length);
 
-std::string a2b_hex(const char* hex_data);
+SpdyString a2b_hex(const char* hex_data);
 
 // Returns a SHA1 HashValue in which each byte has the value |label|.
 HashValue GetTestHashValue(uint8_t label);
 
 // Returns SHA1 pinning header for the of the base64 encoding of
 // GetTestHashValue(|label|).
-std::string GetTestPin(uint8_t label);
+SpdyString GetTestPin(uint8_t label);
 
 // Adds a pin for |host| to |state|.
 void AddPin(TransportSecurityState* state,
-            const std::string& host,
+            const SpdyString& host,
             uint8_t primary_label,
             uint8_t backup_label);