Sprinkle some defensiveness into the UI tests so that they don't explode if t...

chrome/browser/crash_recovery_uitest.cc

 // Copyright (c) 2006-2008 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/file_path.h"
 #include "base/platform_thread.h"
 #include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/ui/ui_test.h"
 #include "net/base/net_util.h"
@@ skipping 10 matching lines @@
 
   // The title of the active tab should change each time this URL is loaded.
   GURL url(
       "data:text/html,<script>document.title=new Date().valueOf()</script>");
 
   NavigateToURL(url);
 
   std::wstring title1 = GetActiveTabTitle();
 
   scoped_refptr<TabProxy> tab(GetActiveTab());
+  ASSERT_TRUE(tab.get());
 
   // Cause the renderer to crash.
   // TODO: Need to port crash_service.exe.
 #if defined(OS_WIN)
   expected_crashes_ = 1;
 #endif
   tab->NavigateToURLAsync(GURL("about:crash"));
 
   // Wait for the browser to notice the renderer crash.
   PlatformThread::Sleep(1000);
@@ skipping 17 matching lines @@
   FilePath test_file(test_data_directory_);
   test_file = test_file.AppendASCII("title2.html");
   GURL url(net::FilePathToFileURL(test_file));
 
   NavigateToURL(url);
 
   const std::wstring title(L"Title Of Awesomeness");
   EXPECT_EQ(title, GetActiveTabTitle());
 
   scoped_refptr<TabProxy> tab(GetActiveTab());
+  ASSERT_TRUE(tab.get());
 
   // Cause the renderer to crash.
   // TODO: Need to port crash_service.exe.
 #if defined(OS_WIN)
   expected_crashes_ = 1;
 #endif
 
   tab->NavigateToURLAsync(GURL("about:crash"));
 
   // Wait for the browser to notice the renderer crash.
   PlatformThread::Sleep(1000);
 
   scoped_refptr<BrowserProxy> browser_proxy(automation()->GetBrowserWindow(0));
   ASSERT_TRUE(browser_proxy->AppendTab(url));
 
   // Ensure the title of the new tab is updated, indicating that the navigation
   // entry was properly committed.
   EXPECT_EQ(title, GetActiveTabTitle());
 }