Update extensions with Drag-and-Drop in extension settings page.

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 d2ab087c1f4e2ebc7d32e106c98343d294a09149..a6dfa58750a95fe35384a8037284a54758a8e12c 100644
--- a/chrome/browser/extensions/extension_install_prompt.h
+++ b/chrome/browser/extensions/extension_install_prompt.h
@@ -57,6 +57,7 @@ class ExtensionInstallPrompt
     PERMISSIONS_PROMPT,
     EXTERNAL_INSTALL_PROMPT,
     POST_INSTALL_PERMISSIONS_PROMPT,
+    UPDATE_PROMPT,
     NUM_PROMPT_TYPES
   };
 
@@ -290,6 +291,13 @@ class ExtensionInstallPrompt
   virtual void ReviewPermissions(Delegate* delegate,
                                  const extensions::Extension* extension);
 
+  // This is called by the installer to verify whether the update should
+  // proceed.
+  //
+  // We *MUST* eventually call either Proceed() or Abort() on |delegate|.
+  virtual void ConfirmUpdate(Delegate* delegate,
+                             const extensions::Extension* extension);
+
   // Installation was successful. This is declared virtual for testing.
   virtual void OnInstallSuccess(const extensions::Extension* extension,
                                 SkBitmap* icon);