Introduce HostID and de-couple Extensions from "script injection System" [browser side]

chrome/common/extensions/manifest_handlers/content_scripts_handler.cc

Index: chrome/common/extensions/manifest_handlers/content_scripts_handler.cc
diff --git a/chrome/common/extensions/manifest_handlers/content_scripts_handler.cc b/chrome/common/extensions/manifest_handlers/content_scripts_handler.cc
index 7f7cba97a23f6ed9ec4d224d4045705af49098b8..759bff168a8264b71ac5e5bbc139f822aea58e74 100644
--- a/chrome/common/extensions/manifest_handlers/content_scripts_handler.cc
+++ b/chrome/common/extensions/manifest_handlers/content_scripts_handler.cc
@@ -13,6 +13,7 @@
 #include "base/values.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/common/url_constants.h"
+#include "extensions/common/consumer.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_resource.h"
@@ -419,7 +420,9 @@ bool ContentScriptsHandler::Parse(Extension* extension, base::string16* error) {
       return false;  // Failed to parse script context definition.
     }
 
-    user_script.set_extension_id(extension->id());
+    ConsumerID id(ConsumerID::EXTENSIONS, extension->id(), ConsumerID::TAB,
+                  ConsumerID::kDefaultInstanceID);
+    user_script.set_consumer_id(id);
     if (extension->converted_from_user_script()) {
       user_script.set_emulate_greasemonkey(true);
       // Greasemonkey matches all frames.