Add "UninstallReason" parameter to ExtensionRegistryObserver::OnExtensionUninstalled.

extensions/browser/extension_registry_observer.h

Index: extensions/browser/extension_registry_observer.h
diff --git a/extensions/browser/extension_registry_observer.h b/extensions/browser/extension_registry_observer.h
index 3ba22c7e49b8e3d829383a3c52dedf2988d30eb4..31573b66a214cef9215e614484acef6450cc75a8 100644
--- a/extensions/browser/extension_registry_observer.h
+++ b/extensions/browser/extension_registry_observer.h
@@ -5,6 +5,7 @@
 #ifndef EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 #define EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 
+#include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/extension.h"
 
 namespace content {
@@ -69,7 +70,8 @@ class ExtensionRegistryObserver {
   // Called after an extension is uninstalled. The extension no longer exists in
   // any of the ExtensionRegistry sets (enabled, disabled, etc.).
   virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
-                                      const Extension* extension) {}
+                                      const Extension* extension,
+                                      UninstallReason reason) {}
 
   // Notifies observers that the observed object is going away.
   virtual void OnShutdown(ExtensionRegistry* registry) {}