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

chrome/common/extensions/manifest_handlers/content_scripts_handler.cc

 // Copyright (c) 2013 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/common/extensions/manifest_handlers/content_scripts_handler.h"
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/error_utils.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_resource.h"
+#include "extensions/common/host_id.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/manifest_handlers/permissions_parser.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "extensions/common/url_pattern.h"
 #include "extensions/common/url_pattern_set.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
 namespace extensions {
 
@@ skipping 383 matching lines @@
 
     UserScript user_script;
     if (!LoadUserScriptFromDictionary(script_dict,
                                       i,
                                       extension,
                                       error,
                                       &user_script)) {
       return false;  // Failed to parse script context definition.
     }
 
-    user_script.set_extension_id(extension->id());
+    HostID id(HostID::EXTENSIONS, extension->id());
+    user_script.set_host_id(id);

[Devlin, 2015/01/26 20:12:09]

nit: inline HostID construction.

[Xi Han, 2015/01/26 23:27:53]

Done.

     if (extension->converted_from_user_script()) {
       user_script.set_emulate_greasemonkey(true);
       // Greasemonkey matches all frames.
       user_script.set_match_all_frames(true);
     }
     user_script.set_id(UserScript::GenerateUserScriptID());
     content_scripts_info->content_scripts.push_back(user_script);
   }
   extension->SetManifestData(keys::kContentScripts,
                              content_scripts_info.release());
@@ skipping 39 matching lines @@
       if (!IsScriptValid(path, css_script.relative_path(),
                          IDS_EXTENSION_LOAD_CSS_FAILED, error))
         return false;
     }
   }
 
   return true;
 }
 
 }  // namespace extensions