Revert of Disable flaky WebNavigationApiTest.CrossProcessHistory.

chrome/browser/extensions/api/web_navigation/web_navigation_apitest.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 <list>
 #include <set>
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 731 matching lines @@
   DelayLoadStartAndExecuteJavascript call_script4(
       test_navigation_listener(),
       embedded_test_server()->GetURL("/test4"),
       "updateFragment()",
       base::StringPrintf("g.html?%u#foo", embedded_test_server()->port()));
 
   ASSERT_TRUE(RunExtensionTest("webnavigation/crossProcessFragment"))
       << message_;
 }
 
-// crbug.com/708139.
-IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, DISABLED_CrossProcessHistory) {
+IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, CrossProcessHistory) {
   ASSERT_TRUE(StartEmbeddedTestServer());
 
   // See crossProcessHistory/e.html.
   DelayLoadStartAndExecuteJavascript call_script2(
       test_navigation_listener(),
       embedded_test_server()->GetURL("/test2"),
       "updateHistory()",
       "empty.html");
 
   // See crossProcessHistory/h.html.
@@ skipping 46 matching lines @@
           "extensions/api_test/webnavigation/crash/b.html",
       embedded_test_server()->port()));
   ui_test_utils::NavigateToURL(browser(), url);
 
   ASSERT_TRUE(catcher.GetNextResult()) << catcher.message();
 }
 
 #endif
 
 }  // namespace extensions