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

net/test/python_utils.cc

 // Copyright (c) 2011 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 "net/test/python_utils.h"
 
 #include "base/base_paths.h"
+#include "base/command_line.h"
 #include "base/environment.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/utf_string_conversions.h"
 
 const char kPythonPathEnv[] = "PYTHONPATH";
 
@@ skipping 78 matching lines @@
       return false;
     }
   }
   generated_code_dir = *dir;
 #endif
   *dir = generated_code_dir.Append(kPyProto);
   VLOG(2) << "Found " << kPyProto.value() << " in " << dir->value();
   return true;
 }
 
-bool GetPythonRunTime(FilePath* dir) {
+bool GetPythonCommand(CommandLine* python_cmd) {
+  DCHECK(python_cmd);
+  FilePath dir;
 #if defined(OS_WIN)
-  if (!PathService::Get(base::DIR_SOURCE_ROOT, dir))
+  if (!PathService::Get(base::DIR_SOURCE_ROOT, &dir))
     return false;
-  *dir = dir->Append(FILE_PATH_LITERAL("third_party"))
-      .Append(FILE_PATH_LITERAL("python_26"))
-      .Append(FILE_PATH_LITERAL("python.exe"));
+  dir = dir.Append(FILE_PATH_LITERAL("third_party"))
+           .Append(FILE_PATH_LITERAL("python_26"))
+           .Append(FILE_PATH_LITERAL("python.exe"));
 #elif defined(OS_POSIX)
-  *dir = FilePath("python");
+  dir = FilePath("python");
 #endif
+
+  python_cmd->SetProgram(dir);
+
+#if defined(OS_POSIX)
+  // Launch python in unbuffered mode, so that python output doesn't mix with
+  // gtest output in buildbot log files. See http://crbug.com/147368.
+  python_cmd->AppendArg("-u");
+#endif
+
   return true;
 }