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

extensions/common/user_script_unittest.cc

Index: extensions/common/user_script_unittest.cc
diff --git a/extensions/common/user_script_unittest.cc b/extensions/common/user_script_unittest.cc
index 589b55506f3e7d01f5442cc831b5e4d6ec90ff5c..2ba7fea51b411f6431333572f9a388e538fef179 100644
--- a/extensions/common/user_script_unittest.cc
+++ b/extensions/common/user_script_unittest.cc
@@ -193,7 +193,9 @@ TEST(ExtensionUserScriptTest, Pickle) {
   const int64 kId = 12;
   script1.set_id(kId);
   const std::string kExtensionId = "foo";
-  script1.set_extension_id(kExtensionId);
+  ConsumerID id(ConsumerID::EXTENSIONS, kExtensionId, ConsumerID::TAB,
+                ConsumerID::kDefaultInstanceID);
+  script1.set_consumer_id(id);
 
   Pickle pickle;
   script1.Pickle(&pickle);