Fix crash under ExclusiveAccessBubbleViews::AnimationProgressed().

chrome/browser/ui/views/exclusive_access_bubble_views_interactive_uitest.cc

+// Copyright 2017 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/exclusive_access/fullscreen_controller_test.h"
+#include "chrome/browser/ui/views/exclusive_access_bubble_views.h"
+#include "chrome/browser/ui/views/frame/browser_view.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
+
+class ExclusiveAccessBubbleViewsTest : public FullscreenControllerTest,
+                                       public views::WidgetObserver {
+ public:
+  ExclusiveAccessBubbleViewsTest() {}
+
+  ExclusiveAccessBubbleViews* bubble() {
+    BrowserView* browser_view =
+        BrowserView::GetBrowserViewForBrowser(browser());
+    return browser_view->exclusive_access_bubble();
+  }
+
+  // WidgetObserver:
+  void OnWidgetDestroying(views::Widget* widget) override {
+    was_observing_in_destroying_ = widget->HasObserver(bubble());
+    was_destroying_ = true;
+    widget->RemoveObserver(this);
+  }
+
+ protected:
+  bool was_destroying_ = false;
+  bool was_observing_in_destroying_ = false;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ExclusiveAccessBubbleViewsTest);
+};
+
+// Simulate obscure codepaths resulting in the bubble Widget being closed before
+// the ExclusiveAccessBubbleViews destructor asks for it. If a close bypasses
+// the destructor, animations could still be running that attempt to manipulate
+// a destroyed Widget and crash.
+IN_PROC_BROWSER_TEST_F(ExclusiveAccessBubbleViewsTest, NativeClose) {
+  EXPECT_FALSE(bubble());
+  EnterActiveTabFullscreen();
+  EXPECT_TRUE(bubble());
+
+  bubble()->GetView()->GetWidget()->AddObserver(this);
+
+  // Simulate the bubble being closed out from under its controller, which seems
+  // to happen in some odd corner cases, like system log-off while the bubble is
+  // showing.
+  bubble()->GetView()->GetWidget()->CloseNow();
+  EXPECT_FALSE(bubble());
+
+  // Verify that teardown is really happening via OnWidgetDestroyed() rather
+  // than the usual path via the ExclusiveAccessBubbleViews destructor. Since
+  // the destructor always first removes ExclusiveAccessBubbleViews as an
+  // observer before starting the close, checking in OnWidgetDestroyed that it's
+  // still observing achieves this.
+  EXPECT_TRUE(was_observing_in_destroying_);
+  EXPECT_TRUE(was_destroying_);
+}