Fixes ungraceful handling of destroyed GlobalError GlobalErrorBubbleView.

chrome/browser/ui/views/global_error_bubble_view.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/global_error_bubble_view.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 56 matching lines @@
     : BubbleDialogDelegateView(anchor_view, arrow),
       browser_(browser),
       error_(error) {
   if (!anchor_view)
     SetAnchorRect(gfx::Rect(anchor_point, gfx::Size()));
 }
 
 GlobalErrorBubbleView::~GlobalErrorBubbleView() {}
 
 base::string16 GlobalErrorBubbleView::GetWindowTitle() const {
+  if (!error_)
+    return base::string16();
   return error_->GetBubbleViewTitle();
 }
 
 gfx::ImageSkia GlobalErrorBubbleView::GetWindowIcon() {
-  gfx::Image image = error_->GetBubbleViewIcon();
-  DCHECK(!image.IsEmpty());
+  gfx::Image image;
+  if (error_) {
+    image = error_->GetBubbleViewIcon();
+    DCHECK(!image.IsEmpty());
+  }
   return *image.ToImageSkia();
 }
 
 bool GlobalErrorBubbleView::ShouldShowWindowIcon() const {
   return true;
 }
 
 void GlobalErrorBubbleView::WindowClosing() {
   if (error_)
     error_->BubbleViewDidClose(browser_);
 }
 
 void GlobalErrorBubbleView::Init() {
+  // |error_| is assumed to be valid, and stay valid, at least until Init()
+  // returns.
+
   // Compensate for built-in vertical padding in the anchor view's image.
   set_anchor_view_insets(gfx::Insets(
       GetLayoutConstant(LOCATION_BAR_BUBBLE_ANCHOR_VERTICAL_INSET), 0));
 
   std::vector<base::string16> message_strings(error_->GetBubbleViewMessages());
   std::vector<views::Label*> message_labels;
   for (size_t i = 0; i < message_strings.size(); ++i) {
     views::Label* message_label = new views::Label(message_strings[i]);
     message_label->SetMultiLine(true);
     message_label->SetHorizontalAlignment(gfx::ALIGN_LEFT);
@@ skipping 16 matching lines @@
   }
 
   // These bubbles show at times where activation is sporadic (like at startup,
   // or a new window opening). Make sure the bubble doesn't disappear before the
   // user sees it, if the bubble needs to be acknowledged.
   set_close_on_deactivate(error_->ShouldCloseOnDeactivate());
 }
 
 void GlobalErrorBubbleView::UpdateButton(views::LabelButton* button,
                                          ui::DialogButton type) {
-  BubbleDialogDelegateView::UpdateButton(button, type);
-  if (type == ui::DIALOG_BUTTON_OK &&
-      error_->ShouldAddElevationIconToAcceptButton()) {
-    elevation_icon_setter_.reset(new ElevationIconSetter(
-        button, base::Bind(&GlobalErrorBubbleView::SizeToContents,
-                           base::Unretained(this))));
+  if (error_) {
+    // UpdateButton can result in calls back in to GlobalErrorBubbleView,
+    // possibly accessing |error_|.
+    BubbleDialogDelegateView::UpdateButton(button, type);
+    if (type == ui::DIALOG_BUTTON_OK &&
+        error_->ShouldAddElevationIconToAcceptButton()) {
+      elevation_icon_setter_.reset(new ElevationIconSetter(
+          button, base::Bind(&GlobalErrorBubbleView::SizeToContents,
+                             base::Unretained(this))));
+    }
   }
 }
 
 bool GlobalErrorBubbleView::ShouldShowCloseButton() const {
   return error_ && error_->ShouldShowCloseButton();
 }
 
 bool GlobalErrorBubbleView::ShouldDefaultButtonBeBlue() const {
   return true;
 }
 
 base::string16 GlobalErrorBubbleView::GetDialogButtonLabel(
     ui::DialogButton button) const {
+  if (!error_)
+    return base::string16();
   return button == ui::DIALOG_BUTTON_OK
              ? error_->GetBubbleViewAcceptButtonLabel()
              : error_->GetBubbleViewCancelButtonLabel();
 }
 
 int GlobalErrorBubbleView::GetDialogButtons() const {
+  if (!error_)
+    return ui::DIALOG_BUTTON_NONE;
   return ui::DIALOG_BUTTON_OK |
          (error_->GetBubbleViewCancelButtonLabel().empty()
               ? 0
               : ui::DIALOG_BUTTON_CANCEL);
 }
 
 bool GlobalErrorBubbleView::Cancel() {
-  error_->BubbleViewCancelButtonPressed(browser_);
+  if (error_)
+    error_->BubbleViewCancelButtonPressed(browser_);
   return true;
 }
 
 bool GlobalErrorBubbleView::Accept() {
-  error_->BubbleViewAcceptButtonPressed(browser_);
+  if (error_)
+    error_->BubbleViewAcceptButtonPressed(browser_);
   return true;
 }
 
 bool GlobalErrorBubbleView::Close() {
   // Don't fall through to either Cancel() or Accept().
   return true;
 }
 
 void GlobalErrorBubbleView::CloseBubbleView() {
   GetWidget()->Close();
 }