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

net/spdy/spdy_session_test_util.h

Index: net/spdy/spdy_session_test_util.h
diff --git a/net/spdy/spdy_session_test_util.h b/net/spdy/spdy_session_test_util.h
index 819b15c8da03ae3d6dea6c71c8f12a636305ba1c..ceb385d4b028ca0a7d10f598c98b02de033f956f 100644
--- a/net/spdy/spdy_session_test_util.h
+++ b/net/spdy/spdy_session_test_util.h
@@ -7,10 +7,9 @@
 
 #include <stdint.h>
 
-#include <string>
-
 #include "base/message_loop/message_loop.h"
 #include "base/pending_task.h"
+#include "net/spdy/platform/api/spdy_string.h"
 
 namespace net {
 
@@ -25,8 +24,8 @@ class SpdySessionTestTaskObserver : public base::MessageLoop::TaskObserver {
   // Example:
   //  file_name = "foo.cc"
   //  function = "DoFoo"
-  SpdySessionTestTaskObserver(const std::string& file_name,
-                              const std::string& function_name);
+  SpdySessionTestTaskObserver(const SpdyString& file_name,
+                              const SpdyString& function_name);
   ~SpdySessionTestTaskObserver() override;
 
   // Implements MessageLoop::TaskObserver.
@@ -38,8 +37,8 @@ class SpdySessionTestTaskObserver : public base::MessageLoop::TaskObserver {
 
  private:
   uint16_t executed_count_;
-  std::string file_name_;
-  std::string function_name_;
+  SpdyString file_name_;
+  SpdyString function_name_;
 };
 
 }  // namespace net