Make infobars ignore button clicks when closing.

chrome/browser/tab_contents/infobar.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/tab_contents/infobar.h"
 
 #include <cmath>
 
 #include "build/build_config.h"
 #include "base/logging.h"
@@ skipping 84 matching lines @@
 void InfoBar::CloseSoon() {
   owner_ = NULL;
   MaybeDelete();
 }
 
 void InfoBar::AnimationProgressed(const ui::Animation* animation) {
   RecalculateHeights(false);
 }
 
 void InfoBar::RemoveSelf() {
-  // |owner_| can be NULL here, e.g. because the user clicks the close button
-  // when the infobar is already closing.
-  if (delegate_ && owner_)
-    owner_->infobar_tab_helper()->RemoveInfoBar(delegate_);
+  DCHECK(owner_);
+  owner_->infobar_tab_helper()->RemoveInfoBar(delegate_);
 }
 
 void InfoBar::SetBarTargetHeight(int height) {
   if (bar_target_height_ != height) {
     bar_target_height_ = height;
     RecalculateHeights(false);
   }
 }
 
 int InfoBar::OffsetY(const gfx::Size& prefsize) const {
@@ skipping 57 matching lines @@
 void InfoBar::MaybeDelete() {
   if (!owner_ && delegate_ && (animation_.GetCurrentValue() == 0.0)) {
     if (container_)
       container_->RemoveInfoBar(this);
     delegate_->InfoBarClosed();
     delegate_ = NULL;
   }
 }
 
 #endif  // TOOLKIT_VIEWS || TOOLKIT_GTK