Ensure syncer::internal::GetComputerName returns a UTF-8 string.

sync/util/get_session_name.cc

Index: sync/util/get_session_name.cc
diff --git a/sync/util/get_session_name.cc b/sync/util/get_session_name.cc
index 3a09c51379d393d168fa0fe1d91bb253b81ed1ca..c669e227727cca63e6c661d58640cbec48208871 100644
--- a/sync/util/get_session_name.cc
+++ b/sync/util/get_session_name.cc
@@ -8,6 +8,7 @@
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/location.h"
+#include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "base/task_runner.h"
 
@@ -53,6 +54,7 @@ std::string GetSessionNameSynchronously() {
   if (session_name == "Unknown" || session_name.empty())
     session_name = base::SysInfo::OperatingSystemName();
 
+  DCHECK(base::IsStringUTF8(session_name));
   return session_name;
 }