Use WeakPtr to simplify AutofillPopupControllerImpl memory management

chrome/browser/autofill/autofill_external_delegate.cc

Index: chrome/browser/autofill/autofill_external_delegate.cc
diff --git a/chrome/browser/autofill/autofill_external_delegate.cc b/chrome/browser/autofill/autofill_external_delegate.cc
index 27d2300a77b34949cad7fa82172bb7469d471fd6..1bc339d51f0588471dff640281d1a76654b9a9bd 100644
--- a/chrome/browser/autofill/autofill_external_delegate.cc
+++ b/chrome/browser/autofill/autofill_external_delegate.cc
@@ -46,7 +46,6 @@ AutofillExternalDelegate::AutofillExternalDelegate(
     AutofillManager* autofill_manager)
     : web_contents_(web_contents),
       autofill_manager_(autofill_manager),
-      controller_(NULL),
       password_autofill_manager_(web_contents),
       autofill_query_id_(0),
       display_warning_if_disabled_(false),
@@ -192,8 +191,6 @@ void AutofillExternalDelegate::ApplyAutofillSuggestions(
                     autofill_labels,
                     autofill_icons,
                     autofill_unique_ids);
-
-  web_contents()->GetRenderViewHost()->AddKeyboardListener(controller_);
 }
 
 void AutofillExternalDelegate::SetCurrentDataListValues(
@@ -207,6 +204,18 @@ void AutofillExternalDelegate::SetCurrentDataListValues(
   data_list_unique_ids_ = data_list_unique_ids;
 }
 
+void AutofillExternalDelegate::OnPopupShown(
+    content::KeyboardListener* listener) {
+  if (web_contents_)
+    web_contents_->GetRenderViewHost()->AddKeyboardListener(listener);
+}
+
+void AutofillExternalDelegate::OnPopupHidden(
+    content::KeyboardListener* listener) {
+  if (web_contents_)
+    web_contents_->GetRenderViewHost()->RemoveKeyboardListener(listener);
+}
+
 void AutofillExternalDelegate::DidSelectSuggestion(int identifier) {
   ClearPreviewedForm();
 
@@ -268,17 +277,10 @@ void AutofillExternalDelegate::ClearPreviewedForm() {
   }
 }
 
-void AutofillExternalDelegate::ControllerDestroyed() {
-  web_contents()->GetRenderViewHost()->RemoveKeyboardListener(controller_);
-  controller_ = NULL;
-}
-
 void AutofillExternalDelegate::HideAutofillPopup() {
   if (controller_) {
     controller_->Hide();
-    // Go ahead and invalidate |controller_|. After calling Hide(), it won't
-    // inform |this| of its destruction.
-    ControllerDestroyed();
+    OnPopupHidden(controller_.get());
   }
 }