Made it possible to tell whether an extension is being installed or updated.

chrome/common/extensions/extension.cc

 // Copyright (c) 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.
 
 #include "chrome/common/extensions/extension.h"
 
 #include "base/base64.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 1723 matching lines @@
                              Manifest::Location location)
     : extension_id(id),
       extension_path(path),
       extension_location(location) {
   if (manifest)
     extension_manifest.reset(manifest->DeepCopy());
 }
 
 ExtensionInfo::~ExtensionInfo() {}
 
+InstalledExtensionInfo::InstalledExtensionInfo(
+    const Extension* extension,
+    bool is_update)
+    : extension(extension),
+      is_update(is_update) {}
+
 UnloadedExtensionInfo::UnloadedExtensionInfo(
     const Extension* extension,
     extension_misc::UnloadedExtensionReason reason)
-  : reason(reason),
-    already_disabled(false),
-    extension(extension) {}
+    : reason(reason),
+      already_disabled(false),
+      extension(extension) {}
 
 UpdatedExtensionPermissionsInfo::UpdatedExtensionPermissionsInfo(
     const Extension* extension,
     const PermissionSet* permissions,
     Reason reason)
     : reason(reason),
       extension(extension),
       permissions(permissions) {}
 
 }   // namespace extensions