Change NotifyAppList*() functions into observers on a ProfileKeyedService.

chrome/browser/extensions/install_tracker.h

Index: chrome/browser/extensions/install_tracker.h
diff --git a/chrome/browser/extensions/install_tracker.h b/chrome/browser/extensions/install_tracker.h
new file mode 100644
index 0000000000000000000000000000000000000000..a15dd53cae694c7a55c036b594471e2bf580ed9b
--- /dev/null
+++ b/chrome/browser/extensions/install_tracker.h
@@ -0,0 +1,43 @@
+// Copyright 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_INSTALL_TRACKER_H_
+#define CHROME_BROWSER_EXTENSIONS_INSTALL_TRACKER_H_
+
+#include "base/observer_list.h"
+#include "chrome/browser/extensions/install_observer.h"

[tfarina, 2013/02/25 23:43:02]

ObserverList doesn't allow you to forward declare this instead?

[koz (OOO until 15th September), 2013/02/26 00:10:51]

No, alas :-(

+#include "chrome/browser/profiles/profile_keyed_service.h"
+
+namespace gfx {
+class ImageSkia;
+}
+
+namespace extensions {
+
+class InstallTracker : public ProfileKeyedService {
+ public:
+  InstallTracker();
+  virtual ~InstallTracker();
+
+  void AddObserver(InstallObserver* observer);
+  void RemoveObserver(InstallObserver* observer);
+
+  void OnBeginExtensionInstall(
+      const std::string& extension_id,
+      const std::string& extension_name,
+      const gfx::ImageSkia& installing_icon,
+      bool is_app);
+  void OnDownloadProgress(const std::string& extension_id,
+                          int percent_downloaded);
+  void OnInstallFailure(const std::string& extension_id);
+
+ private:
+  ObserverList<InstallObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(InstallTracker);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_INSTALL_TRACKER_H_