Fix flakiness in Chrome Frame HeaderTest.

chrome_frame/test/header_test.cc

Index: chrome_frame/test/header_test.cc
diff --git a/chrome_frame/test/header_test.cc b/chrome_frame/test/header_test.cc
index 49c667dc1b2de9b7d431ee556a84ef36623b8aa0..0e61c84046c2436108b9f790e34371d70deb9b14 100644
--- a/chrome_frame/test/header_test.cc
+++ b/chrome_frame/test/header_test.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -39,7 +39,8 @@ class TestData {
     std::ostringstream headers;
     headers << "HTTP/1.1 200 OK\r\n"
             << "Connection: close\r\n"
-            << "Content-Type: text/html\r\n";
+            << "Content-Type: text/html\r\n"
+            << "Cache-Control: no-cache\r\n";
     if (in_header_) {
       headers << "X-UA-COMPATIBLE: " << value_ << "\r\n";
     }