Don't use $USER for Local Login check

remoting/base/util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/base/util.h"
 
 #include <math.h>
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "base/time.h"
 #include "media/base/video_frame.h"
 #include "media/base/yuv_convert.h"
 #include "third_party/skia/include/core/SkRegion.h"
 
+#if defined(OS_POSIX)
+#include <pwd.h>
+#include <sys/types.h>
+#include <unistd.h>
+#endif  // defined(OS_POSIX)
+
 using media::VideoFrame;
 
 namespace remoting {
 
 enum { kBytesPerPixelRGB32 = 4 };
 
 // Do not write LOG messages in this routine since it is called from within
 // our LOG message handler. Bad things will happen.
 std::string GetTimestampString() {
   base::Time t = base::Time::NowFromSystemTime();
@@ skipping 278 matching lines @@
           return false;
       }
 
       ++ptr;
     }
   }
 
   return true;
 }
 
+std::string GetUsername() {
+#if defined(OS_POSIX)
+  long buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
+  if (buf_size <= 0)
+    return std::string();
+  scoped_array<char> buf(new char[buf_size]);
+  struct passwd passwd;
+  struct passwd* passwd_result = NULL;
+  getpwuid_r(getuid(), &passwd, buf.get(), buf_size, &passwd_result);
+  if (!passwd_result)
+    return std::string();
+  return std::string(passwd_result->pw_name);
+#else  // !defined(OS_POSIX)
+  return std::string();
+#endif  // defined(OS_POSIX)
+}
+
 }  // namespace remoting