Reland: Take 2: Force python test server output to be unbuffered, so it doesn't mix with gtest outpu

net/test/local_test_server_posix.cc

Index: net/test/local_test_server_posix.cc
diff --git a/net/test/local_test_server_posix.cc b/net/test/local_test_server_posix.cc
index 7afd422b94a6e1980a5f1e4019fbd0198ca58f8c..eda65fda605ab3446ffb9586a0356d2a6d7fc1a0 100644
--- a/net/test/local_test_server_posix.cc
+++ b/net/test/local_test_server_posix.cc
@@ -97,9 +97,11 @@ namespace net {
 bool LocalTestServer::LaunchPython(const FilePath& testserver_path) {
   // Log is useful in the event you want to run a nearby script (e.g. a test) in
   // the same environment as the TestServer.
-  VLOG(1) << "LaunchPython called with PYTHONPATH = " <<
-          getenv(kPythonPathEnv);
-  CommandLine python_command(FilePath(FILE_PATH_LITERAL("python")));
+  VLOG(1) << "LaunchPython called with PYTHONPATH = " << getenv(kPythonPathEnv);
+
+  CommandLine python_command(CommandLine::NO_PROGRAM);
+  if (!GetPythonCommand(&python_command))
+    return false;
 
   python_command.AppendArgPath(testserver_path);
   if (!AddCommandLineArguments(&python_command))