Add a function triggering extension installed to ExtensionRegistryObserver

extensions/browser/extension_registry_observer.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 #define EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 
 #include "extensions/common/extension.h"
 
 namespace content {
@@ skipping 15 matching lines @@
   // in the enabled_extensions set of ExtensionRegistry.
   virtual void OnExtensionLoaded(
       content::BrowserContext* browser_context,
       const Extension* extension) {}
 
   // Called after an extension is unloaded. The extension no longer exists in
   // any of the ExtensionRegistry sets (enabled, disabled, etc.).
   virtual void OnExtensionUnloaded(content::BrowserContext* browser_context,
                                    const Extension* extension,
                                    UnloadedExtensionInfo::Reason reason) {}
+
+  // Called after an extension is installed. The extension will exclusively
+  // exists in any of the ExtensionRegistry sets (enabled, disabled, etc.).

[not at google - send to devlin, 2014/05/14 18:17:50]

How about the second sentence: The extension will be in exactly one of the
ExtensionRegistry sets.

[limasdf, 2014/05/16 01:02:35]

Done. Thank you.

+  virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
+                                    const Extension* extension,
+                                    InstalledExtensionInfo info) {}

[not at google - send to devlin, 2014/05/14 18:17:50]

we should unwrap the arguments of InstalledExtensionInfo in the same way we did
for Unload. That is,
- const Extension* extension
- bool is_update
- const std::string& old_name

[limasdf, 2014/05/16 01:02:35]

Done.

 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_