Create content::WebContentsDestroyedWatcher, use it in many tests.

content/browser/renderer_host/render_view_host_manager_browsertest.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 "base/json/json_reader.h"
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
@@ skipping 301 matching lines @@
   EXPECT_EQ(1u, Shell::windows().size());
   EXPECT_EQ("/files/title2.html",
             shell()->web_contents()->GetLastCommittedURL().path());
 
   // Should have the same SiteInstance.
   scoped_refptr<SiteInstance> noref_site_instance(
       shell()->web_contents()->GetSiteInstance());
   EXPECT_EQ(orig_site_instance, noref_site_instance);
 }
 
-namespace {
-
-class WebContentsDestroyedObserver : public WebContentsObserver {
- public:
-  WebContentsDestroyedObserver(WebContents* web_contents,
-                               const base::Closure& callback)
-      : WebContentsObserver(web_contents),
-        callback_(callback) {
-  }
-
-  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
-    callback_.Run();
-  }
-
- private:
-  base::Closure callback_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebContentsDestroyedObserver);
-};
-
-}  // namespace
-
 // Test for crbug.com/116192.  Targeted links should still work after the
 // named target window has swapped processes.
 IN_PROC_BROWSER_TEST_F(RenderViewHostManagerTest,
                        AllowTargetedNavigationsAfterSwap) {
   // Start two servers with different sites.
   ASSERT_TRUE(test_server()->Start());
   net::SpawnedTestServer https_server(
       net::SpawnedTestServer::TYPE_HTTPS,
       net::SpawnedTestServer::kLocalhost,
       base::FilePath(FILE_PATH_LITERAL("content/test/data")));
@@ skipping 50 matching lines @@
   // Should have swapped back and shown the new window again.
   scoped_refptr<SiteInstance> revisit_site_instance(
       new_shell->web_contents()->GetSiteInstance());
   EXPECT_EQ(orig_site_instance, revisit_site_instance);
 
   // If it navigates away to another process, the original window should
   // still be able to close it (using a cross-process close message).
   NavigateToURL(new_shell, https_server.GetURL("files/title1.html"));
   EXPECT_EQ(new_site_instance,
             new_shell->web_contents()->GetSiteInstance());
-  scoped_refptr<MessageLoopRunner> loop_runner(new MessageLoopRunner);
-  WebContentsDestroyedObserver close_observer(new_shell->web_contents(),
-                                              loop_runner->QuitClosure());
+  WebContentsDestroyedWatcher close_watcher(new_shell->web_contents());
   EXPECT_TRUE(ExecuteScriptAndExtractBool(
       shell()->web_contents(),
       "window.domAutomationController.send(testCloseWindow());",
       &success));
   EXPECT_TRUE(success);
-  loop_runner->Run();
+  close_watcher.Wait();
 }
 
 // Test that setting the opener to null in a window affects cross-process
 // navigations, including those to existing entries.  http://crbug.com/156669.
 // Flaky on windows: http://crbug.com/291249
 #if defined(OS_WIN)
 #define MAYBE_DisownOpener DISABLED_DisownOpener
 #else
 #define MAYBE_DisownOpener DisownOpener
 #endif
@@ skipping 858 matching lines @@
   NavigateToURL(shell(), https_server.GetURL("files/title1.html"));
 
   // Make sure it ends up at the right page.
   WaitForLoadStop(shell()->web_contents());
   EXPECT_EQ(https_server.GetURL("files/title1.html"),
             shell()->web_contents()->GetLastCommittedURL());
   EXPECT_EQ(new_site_instance, shell()->web_contents()->GetSiteInstance());
 }
 
 }  // namespace content