New post-sideload UI:

chrome/browser/extensions/extension_install_prompt.h

Index: chrome/browser/extensions/extension_install_prompt.h
diff --git a/chrome/browser/extensions/extension_install_prompt.h b/chrome/browser/extensions/extension_install_prompt.h
index ce32fef9826e9aed7e45aa47cb70af633a180979..6142342cae0d83df90a847e9687cc91f1d5e37d0 100644
--- a/chrome/browser/extensions/extension_install_prompt.h
+++ b/chrome/browser/extensions/extension_install_prompt.h
@@ -53,6 +53,7 @@ class ExtensionInstallPrompt : public ImageLoadingTracker::Observer,
     BUNDLE_INSTALL_PROMPT,
     RE_ENABLE_PROMPT,
     PERMISSIONS_PROMPT,
+    EXTERNAL_INSTALL_PROMPT,
     NUM_PROMPT_TYPES
   };
 
@@ -233,6 +234,9 @@ class ExtensionInstallPrompt : public ImageLoadingTracker::Observer,
   virtual void ConfirmReEnable(Delegate* delegate,
                                const extensions::Extension* extension);
 
+  virtual void ConfirmExternalInstall(Delegate* delegate,

[Jeffrey Yasskin, 2012/10/13 21:17:35]

Comment this function. It might make sense to refactor the comments for the
Confirm*() functions so they have less duplicated text, after which this
function might not need its own comment.

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

Done.

+                                      const extensions::Extension* extension);
+
   // This is called by the extension permissions API to verify whether an
   // extension may be granted additional permissions.
   //