[Chromecast] Allow using process specific pref store paths.

This is to avoid potential conflicts when cast_browser and cast_service
processes are trying to use the same file to back up the PrefService
instances.

Bug: b:191090206
Test: On device
Change-Id: I1b9e869355b7d1fb182285092d3fdca8bd956af8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3319658
Reviewed-by: Sean Topping <[email protected]>
Commit-Queue: Junbo Ke <[email protected]>
Cr-Commit-Position: refs/heads/main@{#949336}
diff --git a/chromecast/browser/pref_service_helper.h b/chromecast/browser/pref_service_helper.h
index 6045d2e7..d5ea2919 100644
--- a/chromecast/browser/pref_service_helper.h
+++ b/chromecast/browser/pref_service_helper.h
@@ -13,6 +13,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread_checker.h"
+#include "chromecast/base/process_types.h"
 #include "components/prefs/pref_service.h"
 
 class PrefRegistrySimple;
@@ -26,7 +27,8 @@
  public:
   // Loads configs from config file. Returns true if successful.
   static std::unique_ptr<PrefService> CreatePrefService(
-      PrefRegistrySimple* registry);
+      PrefRegistrySimple* registry,
+      ProcessType process_type = ProcessType::kCastBrowser);
 
   // Provides names of prefs that take a large amount of storage, and are
   // therefore stored in a different file.