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

chrome/browser/extensions/user_script_loader.h

Index: chrome/browser/extensions/user_script_loader.h
diff --git a/chrome/browser/extensions/user_script_loader.h b/chrome/browser/extensions/user_script_loader.h
index 687bd9c3144aea81f1bc20cca7531a2fb0cdc7fb..76b96b2bcae136a405a1b6d5b75f61427f4eae17 100644
--- a/chrome/browser/extensions/user_script_loader.h
+++ b/chrome/browser/extensions/user_script_loader.h
@@ -10,13 +10,12 @@
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/shared_memory.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
-#include "extensions/browser/extension_registry_observer.h"
-#include "extensions/common/extension.h"
-#include "extensions/common/extension_set.h"
+#include "extensions/common/consumer.h"
 #include "extensions/common/user_script.h"
 
 namespace base {
@@ -33,10 +32,6 @@ class Profile;
 namespace extensions {
 
 class ContentVerifier;
-class ExtensionRegistry;
-
-typedef std::map<ExtensionId, ExtensionSet::ExtensionPathAndDefaultLocale>
-    ExtensionsInfo;
 
 // Manages one "logical unit" of user scripts in shared memory by constructing a
 // new shared memory region when the set of scripts changes. Also notifies
@@ -45,21 +40,28 @@ typedef std::map<ExtensionId, ExtensionSet::ExtensionPathAndDefaultLocale>
 // of this class are embedded within classes with names ending in
 // UserScriptMaster. These "master" classes implement the strategy for which
 // scripts to load/unload on this logical unit of scripts.
-class UserScriptLoader : public content::NotificationObserver,
-                         public ExtensionRegistryObserver {
+class UserScriptLoader : public content::NotificationObserver {
  public:
+  using PathAndDefaultLocale = std::pair<base::FilePath, std::string>;
+  using ConsumersInfo = std::map<ConsumerID, PathAndDefaultLocale>;
+
+  using SubstitutionMap = std::map<std::string, std::string>;
+  using LoadUserScriptsFunctionCallback =
+      base::Callback<bool(const ConsumerID&,
+                          UserScript::File*,
+                          const SubstitutionMap*,
+                          scoped_refptr<ContentVerifier>)>;
+
   // Parses the includes out of |script| and returns them in |includes|.
   static bool ParseMetadataHeader(const base::StringPiece& script_text,
                                   UserScript* script);
 
+  UserScriptLoader(Profile* profile, const ConsumerID& consumer_id);
+  ~UserScriptLoader() override;
+
   // A wrapper around the method to load user scripts, which is normally run on
   // the file thread. Exposed only for tests.
-  static void LoadScriptsForTest(UserScriptList* user_scripts);
-
-  UserScriptLoader(Profile* profile,
-                   const ExtensionId& owner_extension_id,
-                   bool listen_for_extension_system_loaded);
-  ~UserScriptLoader() override;
+  void LoadScriptsForTest(UserScriptList* user_scripts);
 
   // Add |scripts| to the set of scripts managed by this loader.
   void AddScripts(const std::set<UserScript>& scripts);
@@ -76,25 +78,35 @@ class UserScriptLoader : public content::NotificationObserver,
   // Return true if we have any scripts ready.
   bool scripts_ready() const { return shared_memory_.get() != NULL; }
 
- private:
-  // content::NotificationObserver implementation.
-  void Observe(int type,
-               const content::NotificationSource& source,
-               const content::NotificationDetails& details) override;
+ protected:
+  using ConsumerIDSet = std::set<ConsumerID>;
 
-  // ExtensionRegistryObserver implementation.
-  void OnExtensionUnloaded(content::BrowserContext* browser_context,
-                           const Extension* extension,
-                           UnloadedExtensionInfo::Reason reason) override;
+  // Update |consumers_info_| to contain info for each element of
+  // |changed_consumers_|.
+  virtual void UpdateConsumersInfo() {}
 
-  // Initiates script load when we have been waiting for the extension system
-  // to be ready.
-  void OnExtensionSystemReady();
+  // If the loading of initial set of consumers has finished.
+  virtual bool ready();
 
-  // Returns whether or not it is possible that calls to AddScripts(),
-  // RemoveScripts(), and/or ClearScripts() have caused any real change in the
-  // set of scripts to be loaded.
-  bool ScriptsMayHaveChanged() const;
+  // Returns a function pointer of a static funcion.
+  // Base and derived classes can specify their ways to load user scripts.
+  virtual LoadUserScriptsFunctionCallback GetLoadUserScriptsFunction();
+
+  // Return a ContentVerifier for managing content verification of the loaded
+  // user scripts.
+  virtual ContentVerifier* GetContentVerifier();
+
+  // Notify render process and convert |changed_consumers| to specified types of
+  // consumers.
+  virtual void SendUpdate(content::RenderProcessHost* process,
+                          base::SharedMemoryHandle handle_for_process,
+                          const std::set<ConsumerID>& changed_consumers) {}
+
+  // Load user scripts.
+  static bool LoadScriptContent(const ConsumerID& consumer_id,
+                                UserScript::File* script_file,
+                                const SubstitutionMap* localization_messages,
+                                scoped_refptr<ContentVerifier> verifier);
 
   // Attempt to initiate a load.
   void AttemptLoad();
@@ -103,20 +115,44 @@ class UserScriptLoader : public content::NotificationObserver,
   void OnScriptsLoaded(scoped_ptr<UserScriptList> user_scripts,
                        scoped_ptr<base::SharedMemory> shared_memory);
 
+  // List of scripts from currently-installed extensions we should load.
+  scoped_ptr<UserScriptList> user_scripts_;
+
+  // Maps consumer info needed for localization to a host ID.
+  ConsumersInfo consumers_info_;
+
+  // The IDs of the extensions which changed in the last update sent to the
+  // renderer.
+  ConsumerIDSet changed_consumers_;
+
+  // The profile for which the scripts managed here are installed.
+  Profile* profile_;
+
+  // ID of the consumer that owns these scripts, if any. This is only set to a
+  // non-empty value for declarative user script shared memory regions.
+  ConsumerID consumer_id_;
+
+ private:
+  // content::NotificationObserver implementation.
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
+  // Returns whether or not it is possible that calls to AddScripts(),
+  // RemoveScripts(), and/or ClearScripts() have caused any real change in the
+  // set of scripts to be loaded.
+  bool ScriptsMayHaveChanged() const;
+
   // Sends the renderer process a new set of user scripts. If
-  // |changed_extensions| is not empty, this signals that only the scripts from
-  // those extensions should be updated. Otherwise, all extensions will be
+  // |changed_consumers| is not empty, this signals that only the scripts from
+  // those consumers should be updated. Otherwise, all consumers will be
   // updated.
   void SendUpdate(content::RenderProcessHost* process,
                   base::SharedMemory* shared_memory,
-                  const std::set<ExtensionId>& changed_extensions);
-
-  // Add to |changed_extensions_| those extensions referred to by |scripts|.
-  void ExpandChangedExtensions(const std::set<UserScript>& scripts);
+                  const ConsumerIDSet& changed_consumers);
 
-  // Update |extensions_info_| to contain info for each element of
-  // |changed_extensions_|.
-  void UpdateExtensionsInfo();
+  // Add to |changed_consumers_| those consumers referred to by |scripts|.
+  void ExpandChangedConsumers(const std::set<UserScript>& scripts);
 
   bool is_loading() const {
     // Ownership of |user_scripts_| is passed to the file thread when loading.
@@ -129,12 +165,6 @@ class UserScriptLoader : public content::NotificationObserver,
   // Contains the scripts that were found the last time scripts were updated.
   scoped_ptr<base::SharedMemory> shared_memory_;
 
-  // List of scripts from currently-installed extensions we should load.
-  scoped_ptr<UserScriptList> user_scripts_;
-
-  // Maps extension info needed for localization to an extension ID.
-  ExtensionsInfo extensions_info_;
-
   // The mutually-exclusive sets of scripts that were added or removed since the
   // last script load.
   std::set<UserScript> added_scripts_;
@@ -144,14 +174,6 @@ class UserScriptLoader : public content::NotificationObserver,
   // additions and removals on the next script load.
   bool clear_scripts_;
 
-  // The IDs of the extensions which changed in the last update sent to the
-  // renderer.
-  ExtensionIdSet changed_extensions_;
-
-  // If the extensions service has finished loading its initial set of
-  // extensions.
-  bool extension_system_ready_;
-
   // If list of user scripts is modified while we're loading it, we note
   // that we're currently mid-load and then start over again once the load
   // finishes.  This boolean tracks whether another load is pending.
@@ -160,16 +182,6 @@ class UserScriptLoader : public content::NotificationObserver,
   // Whether or not we are currently loading.
   bool is_loading_;
 
-  // The profile for which the scripts managed here are installed.
-  Profile* profile_;
-
-  // ID of the extension that owns these scripts, if any. This is only set to a
-  // non-empty value for declarative user script shared memory regions.
-  ExtensionId owner_extension_id_;
-
-  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
-      extension_registry_observer_;
-
   base::WeakPtrFactory<UserScriptLoader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserScriptLoader);