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

chrome/browser/extensions/api/declarative_content/content_action.h

Index: chrome/browser/extensions/api/declarative_content/content_action.h
diff --git a/chrome/browser/extensions/api/declarative_content/content_action.h b/chrome/browser/extensions/api/declarative_content/content_action.h
index dc39431aed870bfe65d677064bf23bc30e542a05..5b973d9fddae5f8dc225f98b3ca0bba00d0ac4da 100644
--- a/chrome/browser/extensions/api/declarative_content/content_action.h
+++ b/chrome/browser/extensions/api/declarative_content/content_action.h
@@ -67,6 +67,7 @@ class ContentAction : public base::RefCounted<ContentAction> {
   // in case the input is syntactically unexpected.
   static scoped_refptr<ContentAction> Create(
       content::BrowserContext* browser_context,
+      const HostID& host_id,
       const Extension* extension,

[Devlin, 2015/01/26 20:12:08]

We're already passing in an extension to all of these different methods.  Do we
really need to pass in a host id, rather than having the action construct a host
id from the extension object?

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

Yes, because for webUI, we want to pass in the id of webUI (e.g.,  a string of
its url). This id can only be created when <webview> is registering the
declarative content rules.  I think the confusion here is caused by creating a
HostID from ChromeContentRulesRegistry, in fact the HostID should be created in
declarative_api.cc and plumbed to here. The rule registry part will be updated
in a following patch, since de-couple extension is also required.

       const base::Value& json_action,
       std::string* error,
@@ -96,14 +97,17 @@ class RequestContentScript : public ContentAction {
   struct ScriptData;
 
   RequestContentScript(content::BrowserContext* browser_context,
+                       const HostID& host_id,
                        const Extension* extension,
                        const ScriptData& script_data);
   RequestContentScript(DeclarativeUserScriptMaster* master,
+                       const HostID& host_id,
                        const Extension* extension,
                        const ScriptData& script_data);
 
   static scoped_refptr<ContentAction> Create(
       content::BrowserContext* browser_context,
+      const HostID& host_id,
       const Extension* extension,
       const base::DictionaryValue* dict,
       std::string* error,
@@ -111,6 +115,7 @@ class RequestContentScript : public ContentAction {
 
   static scoped_refptr<ContentAction> CreateForTest(
       DeclarativeUserScriptMaster* master,
+      const HostID& host_id,
       const Extension* extension,
       const base::Value& json_action,
       std::string* error,
@@ -137,7 +142,9 @@ class RequestContentScript : public ContentAction {
               ApplyInfo* apply_info) const override;
 
  private:
-  void InitScript(const Extension* extension, const ScriptData& script_data);
+  void InitScript(const HostID& host_id,
+                  const Extension* extension,
+                  const ScriptData& script_data);
 
   void AddScript() {
     DCHECK(master_);