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

chrome/browser/safe_browsing/safe_browsing_test.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.
 //
 // This test uses the safebrowsing test server published at
 // http://code.google.com/p/google-safe-browsing/ to test the safebrowsing
 // protocol implemetation. Details of the safebrowsing testing flow is
 // documented at
 // http://code.google.com/p/google-safe-browsing/wiki/ProtocolTesting
 //
@@ skipping 126 matching lines @@
 
     FilePath pyproto_code_dir;
     if (!GetPyProtoPath(&pyproto_code_dir)) {
       LOG(ERROR) << "Failed to get generated python protobuf dir";
       return false;
     }
     AppendToPythonPath(pyproto_code_dir);
     pyproto_code_dir = pyproto_code_dir.Append(FILE_PATH_LITERAL("google"));
     AppendToPythonPath(pyproto_code_dir);
 
-    FilePath python_runtime;
-    EXPECT_TRUE(GetPythonRunTime(&python_runtime));
-    CommandLine cmd_line(python_runtime);
-    // Make python stdout and stderr unbuffered, to prevent incomplete stderr on
-    // win bots, and also fix mixed up ordering of stdout and stderr.
-    cmd_line.AppendSwitch("-u");
+    CommandLine cmd_line(CommandLine::NO_PROGRAM);
+    EXPECT_TRUE(GetPythonCommand(&cmd_line));
+
     FilePath datafile = testserver_path.Append(datafile_);
     cmd_line.AppendArgPath(testserver);
     cmd_line.AppendArg(base::StringPrintf("--port=%d", kPort_));
     cmd_line.AppendArgNative(FILE_PATH_LITERAL("--datafile=") +
                              datafile.value());
 
     base::LaunchOptions options;
 #if defined(OS_WIN)
     options.start_hidden = true;
 #endif
@@ skipping 469 matching lines @@
   }
 
   // Verifies with server if test is done and waits till server responses.
   EXPECT_EQ(net::URLRequestStatus::SUCCESS,
             safe_browsing_helper->VerifyTestComplete(server_host,
                                                      server_port,
                                                      last_step));
   EXPECT_EQ("yes", safe_browsing_helper->response_data());
   test_server.Stop();
 }