Fixes crash by checking for NULL when showing popup. This can happen

chrome/browser/ui/views/autocomplete/autocomplete_popup_contents_view.cc

 // Copyright (c) 2011 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/autocomplete/autocomplete_popup_contents_view.h"
 
 #include "base/compiler_specific.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_popup_model.h"
 #include "chrome/browser/instant/instant_confirm_dialog.h"
@@ skipping 346 matching lines @@
     popup_ = (new AutocompletePopupWidget)->AsWeakPtr();
     views::Widget::InitParams params(views::Widget::InitParams::TYPE_POPUP);
     params.can_activate = false;
     params.transparent = true;
     params.parent_widget = location_bar_->GetWidget();
     params.bounds = GetPopupBounds();
     popup_->Init(params);
     popup_->SetContentsView(this);
     popup_->MoveAbove(
         GetRelativeWindowForPopup(omnibox_view_->GetNativeView()));
+    if (!popup_.get()) {
+      // For some IMEs GetRelativeWindowForPopup triggers the omnibox to lose
+      // focus, thereby closing (and destroying) the popup.
+      // TODO: this won't be needed once we close the omnibox on input window

[Peter Kasting, 2011/09/12 18:36:52]

? We explicitly wanted to avoid closing the omnibox when the input window was
showing, hence the current code that tries to avoid overlapping the two.

+      // showing.
+      return;
+    }
     popup_->Show();
   } else {
     // Animate the popup shrinking, but don't animate growing larger since that
     // would make the popup feel less responsive.
     start_bounds_ = GetWidget()->GetWindowScreenBounds();
     if (target_bounds_.height() < start_bounds_.height())
       size_animation_.Show();
     else
       start_bounds_ = target_bounds_;
     popup_->SetBounds(GetPopupBounds());
@@ skipping 320 matching lines @@
   opt_in_view_ = NULL;
   PromoCounter* counter = profile_->GetInstantPromoCounter();
   DCHECK(counter);
   counter->Hide();
   if (opt_in) {
     browser::ShowInstantConfirmDialogIfNecessary(
         location_bar_->GetWidget()->GetNativeWindow(), profile_);
   }
   UpdatePopupAppearance();
 }