[Extensions] Don't run unload listeners when an extension is removed

chrome/browser/extensions/extension_unload_browsertest.cc

+// Copyright 2016 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/extensions/extension_browsertest.h"
+#include "chrome/browser/extensions/extension_service.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "ui/base/window_open_disposition.h"
+
+namespace extensions {
+
+using ExtensionUnloadBrowserTest = ExtensionBrowserTest;
+
+IN_PROC_BROWSER_TEST_F(ExtensionUnloadBrowserTest, TestUnload) {
+  // Load an extension that installs unload and beforeunload listeners.
+  const Extension* extension =
+      LoadExtension(test_data_dir_.AppendASCII("unload_listener"));
+  ASSERT_TRUE(extension);
+  std::string id = extension->id();
+  ASSERT_EQ(1, browser()->tab_strip_model()->count());
+  GURL initial_tab_url =
+      browser()->tab_strip_model()->GetWebContentsAt(0)->GetLastCommittedURL();
+  ui_test_utils::NavigateToURLWithDisposition(
+      browser(), extension->GetResourceURL("page.html"),
+      WindowOpenDisposition::NEW_FOREGROUND_TAB,
+      ui_test_utils::BROWSER_TEST_WAIT_FOR_NAVIGATION);
+  EXPECT_EQ(2, browser()->tab_strip_model()->count());
+  extension_service()->UnloadExtension(id,
+                                       UnloadedExtensionInfo::REASON_DISABLE);
+  // There should only be one remaining web contents - the initial one.
+  ASSERT_EQ(1, browser()->tab_strip_model()->count());
+  EXPECT_EQ(
+      initial_tab_url,
+      browser()->tab_strip_model()->GetWebContentsAt(0)->GetLastCommittedURL());
+}
+
+// TODO(devlin): Investigate what to do for embedded iframes.
+
+}  // namespace extensions