Refactoring: de-couple Extensions from "script injection System" [render side] : 1

extensions/browser/guest_view/web_view/web_view_guest.h

Index: extensions/browser/guest_view/web_view/web_view_guest.h
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.h b/extensions/browser/guest_view/web_view/web_view_guest.h
index 2e399ea92c3e057e99c1537674875f4f243e8aa3..cb28c674a7367e72fa00e2a1dd90de171758b2a0 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.h
+++ b/extensions/browser/guest_view/web_view/web_view_guest.h
@@ -7,6 +7,7 @@
 
 #include <vector>
 
+#include "base/callback.h"
 #include "base/observer_list.h"
 #include "content/public/browser/javascript_dialog_manager.h"
 #include "content/public/browser/notification_observer.h"
@@ -56,12 +57,19 @@ class WebViewGuest : public GuestView<WebViewGuest>,
 
   static const char Type[];
 
-  // Return the stored rules registry ID of the given webview. Will generate
+  // Returns the stored rules registry ID of the given webview. Will generate
   // an ID for the first query.
   static int GetOrGenerateRulesRegistryID(
       int embedder_process_id,
       int web_view_instance_id);
 
+  // Returns the stored instance ID of the given guest. The instance ID is
+  // unique per <webview> guest, and is used in script injection.
+  // Will generate an ID for the first query.
+  static int GetOrGenerateUniqueInstanceID(
+      int embedder_process_id,
+      int guest_instance_id);
+
   // Request navigating the guest to the provided |src| URL.
   void NavigateGuest(const std::string& src, bool force_navigation);