Disable flaky MD Settings tests on Windows

chrome/browser/ui/webui/settings/md_settings_ui_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 <string>
 
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/url_constants.h"
@@ skipping 11 matching lines @@
 
 using ui_test_utils::NavigateToURL;
 using content::WaitForLoadStop;
 
 IN_PROC_BROWSER_TEST_F(MdSettingsUITest, ViewSourceDoesntCrash) {
   NavigateToURL(browser(),
       GURL(content::kViewSourceScheme + std::string(":") +
            chrome::kChromeUIMdSettingsURL));
 }
 
-// May not complete on memory bots. TODO(dbeam): investigate and fix.
-// See https://crbug.com/558434 and https://crbug.com/620370.
-#if defined(MEMORY_SANITIZER)
+// May not complete on memory and Windows debug bots. TODO(dbeam): investigate
+// and fix. See https://crbug.com/558434, https://crbug.com/620370 and
+// https://crbug.com/651296.
+#if defined(MEMORY_SANITIZER) || defined(OS_WIN)
 #define MAYBE_BackForwardDoesntCrash DISABLED_BackForwardDoesntCrash
 #else
 #define MAYBE_BackForwardDoesntCrash BackForwardDoesntCrash
 #endif
 
 IN_PROC_BROWSER_TEST_F(MdSettingsUITest, MAYBE_BackForwardDoesntCrash) {
   NavigateToURL(browser(), GURL(chrome::kChromeUIMdSettingsURL));
 
   NavigateToURL(browser(), GURL(chrome::kChromeUINewTabURL));
 
@@ skipping 11 matching lines @@
                               ->GetActiveWebContents()
                               ->GetWebUI()
                               ->GetHandlersForTesting();
 
   for (content::WebUIMessageHandler* handler : handlers) {
     handler->AllowJavascriptForTesting();
     handler->DisallowJavascript();
     handler->AllowJavascriptForTesting();
   }
 }