Kill NOTIFICATION_EXTENSION_REMOVED

chrome/browser/extensions/external_install_ui.cc

Index: chrome/browser/extensions/external_install_ui.cc
diff --git a/chrome/browser/extensions/external_install_ui.cc b/chrome/browser/extensions/external_install_ui.cc
index d2771943e6da391566e271701d14dd8df5aa8690..efa874844ba1805132e9a436504c60832230f130 100644
--- a/chrome/browser/extensions/external_install_ui.cc
+++ b/chrome/browser/extensions/external_install_ui.cc
@@ -7,9 +7,11 @@
 #include <string>
 
 #include "base/bind.h"
+#include "base/callback_forward.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
@@ -119,10 +121,15 @@ class ExternalInstallMenuAlert : public GlobalError,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Callback to notify UI that extension has been removed.
+  void HandleExtensionRemoved(const Extension* extension);
+
  protected:
-  ExtensionService* service_;
+  base::WeakPtr<ExtensionService> service_weak_;
   const Extension* extension_;
   content::NotificationRegistrar registrar_;
+  base::WeakPtrFactory<ExternalInstallMenuAlert> weak_factory_;
+  base::Callback<void(const Extension*)> on_removed_callback_;
 };
 
 // Shows a menu item and a global error bubble, replacing the install dialog.
@@ -240,15 +247,21 @@ void ExternalInstallDialogDelegate::InstallUIAbort(bool user_initiated) {
 ExternalInstallMenuAlert::ExternalInstallMenuAlert(
     ExtensionService* service,
     const Extension* extension)
-    : service_(service),
-      extension_(extension) {
+    : service_weak_(service->AsWeakPtr()),
+      extension_(extension),
+      weak_factory_(this) {
+  on_removed_callback_ = base::Bind(
+      &ExternalInstallMenuAlert::HandleExtensionRemoved,
+      weak_factory_.GetWeakPtr());
+  if (service_weak_.get())
+    service_weak_->RegisterExtensionRemovedCallback(on_removed_callback_);
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
                  content::Source<Profile>(service->profile()));
-  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_REMOVED,
-                 content::Source<Profile>(service->profile()));
 }
 
 ExternalInstallMenuAlert::~ExternalInstallMenuAlert() {
+  if (service_weak_.get())
+    service_weak_->RemoveExtensionRemovedCallback(on_removed_callback_);
 }
 
 GlobalError::Severity ExternalInstallMenuAlert::GetSeverity() {
@@ -275,7 +288,7 @@ string16 ExternalInstallMenuAlert::MenuItemLabel() {
 }
 
 void ExternalInstallMenuAlert::ExecuteMenuItem(Browser* browser) {
-  ShowExternalInstallDialog(service_, browser, extension_);
+  ShowExternalInstallDialog(service_weak_.get(), browser, extension_);
 }
 
 bool ExternalInstallMenuAlert::HasBubbleView() {
@@ -316,15 +329,29 @@ void ExternalInstallMenuAlert::Observe(
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   // The error is invalidated if the extension has been loaded or removed.
-  DCHECK(type == chrome::NOTIFICATION_EXTENSION_LOADED ||
-         type == chrome::NOTIFICATION_EXTENSION_REMOVED);
+  DCHECK(type == chrome::NOTIFICATION_EXTENSION_LOADED);
   const Extension* extension = content::Details<const Extension>(details).ptr();
   if (extension != extension_)
     return;
-  GlobalErrorService* error_service =
-      GlobalErrorServiceFactory::GetForProfile(service_->profile());
-  error_service->RemoveGlobalError(this);
-  service_->AcknowledgeExternalExtension(extension_->id());
+  if (service_weak_.get()) {
+    GlobalErrorService* error_service =
+        GlobalErrorServiceFactory::GetForProfile(service_weak_->profile());
+    error_service->RemoveGlobalError(this);
+    service_weak_->AcknowledgeExternalExtension(extension_->id());
+  }
+  delete this;
+}
+
+void ExternalInstallMenuAlert::HandleExtensionRemoved(
+    const Extension* extension) {
+  if (extension != extension_)
+    return;
+  if (service_weak_.get()) {
+    GlobalErrorService* error_service =
+        GlobalErrorServiceFactory::GetForProfile(service_weak_->profile());
+    error_service->RemoveGlobalError(this);
+    service_weak_->AcknowledgeExternalExtension(extension_->id());
+  }
   delete this;
 }