app_shell: Extract extension runtime data from ExtensionService

extensions/browser/extension_registry.cc

Index: extensions/browser/extension_registry.cc
diff --git a/extensions/browser/extension_registry.cc b/extensions/browser/extension_registry.cc
index bc5247cdce2002d9cadaf121809d15f0bcbc8e59..5c4cf5d4a90eb2215659b9f91b9177e96d828d76 100644
--- a/extensions/browser/extension_registry.cc
+++ b/extensions/browser/extension_registry.cc
@@ -6,6 +6,7 @@
 
 #include "base/strings/string_util.h"
 #include "extensions/browser/extension_registry_factory.h"
+#include "extensions/browser/extension_registry_observer.h"
 
 namespace extensions {
 
@@ -17,6 +18,20 @@ ExtensionRegistry* ExtensionRegistry::Get(content::BrowserContext* context) {
   return ExtensionRegistryFactory::GetForBrowserContext(context);
 }
 
+void ExtensionRegistry::AddObserver(ExtensionRegistryObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ExtensionRegistry::RemoveObserver(ExtensionRegistryObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void ExtensionRegistry::TriggerOnUnloaded(const Extension* extension) {
+  DCHECK(!enabled_extensions_.Contains(extension->id()));
+  FOR_EACH_OBSERVER(
+      ExtensionRegistryObserver, observers_, OnExtensionUnloaded(extension));
+}
+
 const Extension* ExtensionRegistry::GetExtensionById(const std::string& id,
                                                      int include_mask) const {
   std::string lowercase_id = StringToLowerASCII(id);