Use separated theme service for tor profile

As we use different theme colors for tor window(previously, same with private), we should
differentiate tor and private profile from ThemeHelper. However, upstream chromium uses
only two kinds of theme provider. One for orignal theme provider and the other is incognito
theme provider. If we want to add another theme provider for tor, it will add many patch files.
So, I think using different theme service for tor profile is simplest way to have tor specific
theme colors.

chromium_src/chrome/browser/themes/theme_service_factory.cc

@@ -15,5 +15,9 @@
 #define BRAVE_THEMESERVICEFACTORY_BUILDSERVICEINSTANCEFOR
 #endif
 
+#define  BRAVE_THEMESERVICEFACTORY_GETBROWSERCONTEXTTOUSE \
+  if (context->IsTor()) return context;
+
 #include "../../../../../chrome/browser/themes/theme_service_factory.cc"
 #undef BRAVE_THEMESERVICEFACTORY_BUILDSERVICEINSTANCEFOR
+#undef  BRAVE_THEMESERVICEFACTORY_GETBROWSERCONTEXTTOUSE

patches/chrome-browser-themes-theme_service_factory.cc.patch

@@ -1,5 +1,5 @@
 diff --git a/chrome/browser/themes/theme_service_factory.cc b/chrome/browser/themes/theme_service_factory.cc
-index caec77bbe3ba59b030622d3a9ff4fb1edd0a476d..b1b48ed7fb8022d6377594754ce1f300b01a8fca 100644
+index caec77bbe3ba59b030622d3a9ff4fb1edd0a476d..e6d475bc2908d5a30376535c8988d8a45db78b36 100644
 --- a/chrome/browser/themes/theme_service_factory.cc
 +++ b/chrome/browser/themes/theme_service_factory.cc
 @@ -77,6 +77,7 @@ ThemeServiceFactory::~ThemeServiceFactory() {}
@@ -10,3 +10,11 @@ index caec77bbe3ba59b030622d3a9ff4fb1edd0a476d..b1b48ed7fb8022d6377594754ce1f300
  #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
    using ThemeService = ThemeServiceAuraLinux;
  #endif
+@@ -108,6 +109,7 @@ void ThemeServiceFactory::RegisterProfilePrefs(
+
+ content::BrowserContext* ThemeServiceFactory::GetBrowserContextToUse(
+     content::BrowserContext* context) const {
++  BRAVE_THEMESERVICEFACTORY_GETBROWSERCONTEXTTOUSE
+   return chrome::GetBrowserContextRedirectedInIncognito(context);
+ }
+