Fix DELETE_EVENT handling in 3 places.

chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc

Index: chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc
diff --git a/chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc b/chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc
index 9e461a5af3be91dc96ae1aa711077c7614194176..1237d52649b672532c2baebeb0528fae4c17fc8f 100644
--- a/chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc
+++ b/chrome/browser/ui/gtk/hung_renderer_dialog_gtk.cc
@@ -34,6 +34,8 @@ class HungRendererDialogGtk {
   void EndForTabContents(TabContents* hung_contents);
 
  private:
+  ~HungRendererDialogGtk();
+
   // The GtkTreeView column ids.
   enum {
     COL_FAVICON,
@@ -65,6 +67,14 @@ HungRendererDialogGtk::HungRendererDialogGtk()
   Init();
 }
 
+HungRendererDialogGtk::~HungRendererDialogGtk() {
+  DCHECK(g_instance == this);
+  g_instance = NULL;
+
+  if (dialog_)
+    gtk_widget_destroy(GTK_WIDGET(dialog_));
+}
+
 void HungRendererDialogGtk::Init() {
   dialog_ = GTK_DIALOG(gtk_dialog_new_with_buttons(
       l10n_util::GetStringUTF8(IDS_BROWSER_HANGMONITOR_RENDERER_TITLE).c_str(),
@@ -77,6 +87,9 @@ void HungRendererDialogGtk::Init() {
       NULL));
   gtk_dialog_set_default_response(dialog_, GTK_RESPONSE_OK);
   g_signal_connect(dialog_, "response", G_CALLBACK(OnResponseThunk), this);
+  // NULL out |dialog_| when it's destroyed.
+  g_signal_connect(dialog_, "destroy",
+                   G_CALLBACK(gtk_widget_destroyed), &dialog_);
 
   // We have an hbox with the frozen icon on the left.  On the right,
   // we have a vbox with the unresponsive text on top and a table of
@@ -183,7 +196,6 @@ void HungRendererDialogGtk::EndForTabContents(TabContents* contents) {
 // When the user clicks a button on the dialog or closes the dialog, this
 // callback is called.
 void HungRendererDialogGtk::OnResponse(GtkWidget* dialog, int response_id) {
-  DCHECK(g_instance == this);
   switch (response_id) {
     case kKillPagesButtonResponse:
       // Kill the process.
@@ -203,9 +215,7 @@ void HungRendererDialogGtk::OnResponse(GtkWidget* dialog, int response_id) {
       NOTREACHED();
   }
 
-  gtk_widget_destroy(GTK_WIDGET(dialog_));
-  delete g_instance;
-  g_instance = NULL;
+  delete this;
 }
 
 }  // namespace