add customized printing setting for headless

headless/lib/headless_content_main_delegate.cc

Index: headless/lib/headless_content_main_delegate.cc
diff --git a/headless/lib/headless_content_main_delegate.cc b/headless/lib/headless_content_main_delegate.cc
index 067ef27193dd9feb922c84c636bb7d6393778e3e..2e92cabed45be1ff3839525443242d16925fae8e 100644
--- a/headless/lib/headless_content_main_delegate.cc
+++ b/headless/lib/headless_content_main_delegate.cc
@@ -33,6 +33,12 @@
 #include "headless/embedded_resource_pak.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "base/mac/bundle_locations.h"
+#else
+#include "ui/base/ui_base_paths.h"
+#endif
+
 namespace headless {
 namespace {
 // Keep in sync with content/common/content_constants_internal.h.
@@ -241,6 +247,15 @@ void HeadlessContentMainDelegate::InitializeResourceBundle() {
   bool result = PathService::Get(base::DIR_MODULE, &dir_module);
   DCHECK(result);
 
+  // Override locale pak dir to 'headless_locales'.
+  base::FilePath locale_pak =
+      dir_module.AppendASCII(FILE_PATH_LITERAL("headless_locales"));
+#if defined(OS_MACOSX)
+  base::mac::SetOverrideFrameworkBundlePath(locale_pak);
+#else
+  PathService::Override(ui::DIR_LOCALES, locale_pak);
+#endif
+
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   const std::string locale = command_line->GetSwitchValueASCII(switches::kLang);
   ui::ResourceBundle::InitSharedInstanceWithLocale(