New post-sideload UI:

chrome/browser/extensions/external_install_ui.h

Index: chrome/browser/extensions/external_install_ui.h
diff --git a/chrome/browser/extensions/external_install_ui.h b/chrome/browser/extensions/external_install_ui.h
new file mode 100644
index 0000000000000000000000000000000000000000..25b4c5adbf1b9a5d8f4d36385afbf85b40f4c4bf
--- /dev/null
+++ b/chrome/browser/extensions/external_install_ui.h
@@ -0,0 +1,26 @@
+// Copyright (c) 2012 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_EXTERNAL_INSTALL_UI_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_UI_H_
+
+class Browser;
+class ExtensionService;
+
+namespace extensions {
+
+class Extension;
+
+bool AddExternalInstallError(ExtensionService* service,

[Jeffrey Yasskin, 2012/10/15 00:43:59]

Please document these functions.

[Matt Perry, 2012/10/15 19:13:38]

Done.

+                             const Extension* extension);
+void RemoveExternalInstallError(ExtensionService* service);
+
+// Shows the extension install dialog.
+void ShowExternalInstallDialog(ExtensionService* service,

[Matt Perry, 2012/10/15 19:13:38]

I made this a static function in the .cc, since it doesn't need to be public.

+                               Browser* browser,
+                               const Extension* extension);
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_UI_H_