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

chrome/browser/extensions/declarative_user_script_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/declarative_user_script_manager.h"
 
-#include "chrome/browser/extensions/declarative_user_script_master.h"
+#include "chrome/browser/extensions/extension_declarative_user_script_master.h"
 
 namespace extensions {
 
 DeclarativeUserScriptManager::DeclarativeUserScriptManager(Profile* profile)
-    : profile_(profile) {
+    : profile_(profile), current_instance_id_(ConsumerID::kDefaultInstanceID) {
 }
 
 DeclarativeUserScriptManager::~DeclarativeUserScriptManager() {
 }
 
 DeclarativeUserScriptMaster*
 DeclarativeUserScriptManager::GetDeclarativeUserScriptMasterByID(
     const std::string& id) {
-  UserScriptMasterMap::iterator it = declarative_user_script_masters_.find(id);
+  RulesRegistryKey key(id);
+  RulesRegistryKeyToIDMap::iterator it =
+      rules_registry_key_to_id_map_.find(key);
+  if (it != rules_registry_key_to_id_map_.end())
+    return GetDeclarativeUserScriptMasterByID(it->second);
+
+  ConsumerID consumer_id(ConsumerID::EXTENSIONS, id, ConsumerID::TAB,
+                         GetNextID());
+  rules_registry_key_to_id_map_[key] = consumer_id;
+  return CreateDeclarativeUserScriptMaster(consumer_id);
+}
+
+DeclarativeUserScriptMaster*
+DeclarativeUserScriptManager::GetDeclarativeUserScriptMasterByID(
+    const ConsumerID& consumer_id) {
+  UserScriptMasterMap::iterator it =
+      declarative_user_script_masters_.find(consumer_id);
 
   if (it != declarative_user_script_masters_.end())
     return it->second.get();
 
-  linked_ptr<DeclarativeUserScriptMaster> master(
-      new DeclarativeUserScriptMaster(profile_, id));
-  declarative_user_script_masters_[id] = master;
+  return CreateDeclarativeUserScriptMaster(consumer_id);
+}
+
+DeclarativeUserScriptMaster*
+DeclarativeUserScriptManager::CreateDeclarativeUserScriptMaster(
+    const ConsumerID& consumer_id) {
+  linked_ptr<DeclarativeUserScriptMaster> master;
+  switch (consumer_id.host_type()) {
+    case ConsumerID::EXTENSIONS:
+      master.reset(
+          new ExtensionDeclarativeUserScriptMaster(profile_, consumer_id));
+      break;
+    default:
+      master.reset(new DeclarativeUserScriptMaster(profile_, consumer_id));
+  }
+  declarative_user_script_masters_[consumer_id] = master;
   return master.get();
 }
 
-}  // extensions
+int DeclarativeUserScriptManager::GetNextID() {
+  return ++current_instance_id_;
+}
+
+}  // namespace extensions