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"));

[Lei Zhang, 2017/04/20 08:35:58]

AppendASCII and FILE_PATH_LITERAL should never be used together. The former
always wants to take a regular string, and the latter is trying to convert the
regular string into a wide string on Windows.

I think the fact that the trybots are green means they are probably not even
building this file. Which then brings up the question of why does this even have
checks for defined(OS_WIN).

[jzfeng, 2017/04/27 06:56:07]

Done.
Headless chrome is about to be enabled on Windows . It should check for this
file afterwards.

+#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(