Reduce flakiness in chrome_frame_tests.exe by having each run in a clean environment.

chrome_frame/test/chrome_frame_test_utils.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 "chrome_frame/test/chrome_frame_test_utils.h"
 
 #include <atlapp.h>
 #include <atlmisc.h>
 #include <iepmapi.h>
 #include <sddl.h>
@@ skipping 159 matching lines @@
   } else {
     CommandLine cmdline((FilePath(path)));
     cmdline.AppendArgNative(argument);
     if (!base::LaunchProcess(cmdline, base::LaunchOptions(), &process)) {
       LOG(ERROR) << "LaunchProcess failed: " << ::GetLastError();
     }
   }
   return process;
 }
 
-base::ProcessHandle LaunchChrome(const std::wstring& url) {
+base::ProcessHandle LaunchChrome(const std::wstring& url,
+                                 const FilePath& user_data_dir) {
   FilePath path;
   PathService::Get(base::DIR_MODULE, &path);
   path = path.AppendASCII(kChromeImageName);
 
   CommandLine cmd(path);
   cmd.AppendSwitch(switches::kNoFirstRun);
+  if (!user_data_dir.empty())
+    cmd.AppendSwitchPath(switches::kUserDataDir, user_data_dir);
   cmd.AppendArgNative(url);
 
   base::ProcessHandle process = NULL;
   base::LaunchProcess(cmd, base::LaunchOptions(), &process);
   return process;
 }
 
 base::ProcessHandle LaunchIEOnVista(const std::wstring& url) {
   typedef HRESULT (WINAPI* IELaunchURLPtr)(
       const wchar_t* url,
@@ skipping 467 matching lines @@
   wchar_t local_app_data_path[MAX_PATH + 1] = {0};
   SHGetFolderPath(NULL, CSIDL_LOCAL_APPDATA, NULL, SHGFP_TYPE_CURRENT,
                   local_app_data_path);
 
   std::wstring session_history_path = local_app_data_path;
   session_history_path += L"\\Microsoft\\Internet Explorer\\Recovery";
   file_util::Delete(session_history_path, true);
 }
 
 }  // namespace chrome_frame_test