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

content/test/layout_test_http_server.cc

Index: content/test/layout_test_http_server.cc
diff --git a/content/test/layout_test_http_server.cc b/content/test/layout_test_http_server.cc
index 783c5963caec032031f3bf529230f03807ad72ba..dabe9978404c51532a9963897d2ae08b7a4d0ad2 100644
--- a/content/test/layout_test_http_server.cc
+++ b/content/test/layout_test_http_server.cc
@@ -28,6 +28,10 @@ bool PrepareCommandLine(CommandLine* cmd_line) {
     return false;
   cmd_line->SetProgram(python_runtime);
 
+  // Use unbuffered output, so that testserver output doesn't mix with gtest
+  // output in test log files. See http://crbug.com/147368.
+  cmd_line->AppendArg("-u");
+
   FilePath script_path(src_path);
   script_path = script_path.AppendASCII("third_party");
   script_path = script_path.AppendASCII("WebKit");