Store USB device permissions in website settings.

chrome/browser/permissions/permission_context_base.h

Index: chrome/browser/permissions/permission_context_base.h
diff --git a/chrome/browser/permissions/permission_context_base.h b/chrome/browser/permissions/permission_context_base.h
index 6c084e179c48da4dae0045acb35b18fed494336c..26e5bd51d2407904146946ae31853636d3b89103 100644
--- a/chrome/browser/permissions/permission_context_base.h
+++ b/chrome/browser/permissions/permission_context_base.h
@@ -121,6 +121,9 @@ class PermissionContextBase : public KeyedService {
   // Returns the profile associated with this permission context.
   Profile* profile() const;
 
+  // Returns the permission type managed by this context.
+  ContentSettingsType type() const;
+
   // Store the decided permission as a content setting.
   // virtual since the permission might be stored with different restrictions
   // (for example for desktop notifications).