Update viewport_meta setting on any navigation.

content/browser/frame_host/navigation_controller_impl_unittest.cc

 // Copyright 2013 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 "content/browser/frame_host/navigation_controller_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
@@ skipping 1629 matching lines @@
 
   // Normal navigation will preserve redirects in the committed entry.
   main_test_rfh()->PrepareForCommitWithServerRedirect(url2);
   main_test_rfh()->SendNavigateWithModificationCallback(entry_id, true, url1,
                                                         set_redirects_callback);
   NavigationEntryImpl* committed_entry = controller.GetLastCommittedEntry();
   ASSERT_EQ(1U, committed_entry->GetRedirectChain().size());
   EXPECT_EQ(url2, committed_entry->GetRedirectChain()[0]);
 }
 
+// Tests that webkit preferences are updated when user agent override changes.
+TEST_F(NavigationControllerTest, NavigateWithUserAgentOverrideChange) {
+  NavigationControllerImpl& controller = controller_impl();
+
+  int change_counter = 0;
+  test_rvh()->set_webkit_preferences_changed_counter(&change_counter);
+
+  const GURL url1("http://foo/1");
+  const GURL url2("http://foo/2");
+
+  NavigationController::LoadURLParams load_params(url1);
+  load_params.referrer =
+      Referrer(GURL("http://referrer"), blink::WebReferrerPolicyDefault);
+  load_params.transition_type = ui::PAGE_TRANSITION_GENERATED;
+  load_params.extra_headers = "content-type: text/plain";
+  load_params.load_type = NavigationController::LOAD_TYPE_DEFAULT;
+  load_params.is_renderer_initiated = false;
+  load_params.override_user_agent = NavigationController::UA_OVERRIDE_FALSE;
+  load_params.transferred_global_request_id = GlobalRequestID(2, 3);
+  controller.LoadURLWithParams(load_params);
+  int entry_id = controller.GetPendingEntry()->GetUniqueID();
+
+  EXPECT_EQ(false, controller.GetPendingEntry()->GetIsOverridingUserAgent());
+
+  main_test_rfh()->PrepareForCommit();
+  main_test_rfh()->SendNavigate(entry_id, true, url1);
+
+  NavigationController::LoadURLParams load_params2(url2);
+  load_params2.referrer =
+      Referrer(GURL("http://referrer"), blink::WebReferrerPolicyDefault);
+  load_params2.transition_type = ui::PAGE_TRANSITION_GENERATED;
+  load_params2.extra_headers = "content-type: text/plain";
+  load_params2.load_type = NavigationController::LOAD_TYPE_DEFAULT;
+  load_params2.is_renderer_initiated = false;
+  load_params2.override_user_agent = NavigationController::UA_OVERRIDE_TRUE;
+  load_params2.transferred_global_request_id = GlobalRequestID(4, 5);
+
+  controller.LoadURLWithParams(load_params2);
+  entry_id = controller.GetPendingEntry()->GetUniqueID();
+  EXPECT_EQ(true, controller.GetPendingEntry()->GetIsOverridingUserAgent());
+
+  main_test_rfh()->PrepareForCommit();
+  main_test_rfh()->SendNavigate(entry_id, true, url2);
+
+  EXPECT_EQ(2, change_counter);

[Charlie Reis, 2017/01/12 19:37:54]

Would this test fail without your fix?  I thought the bug was that the
preferences didn't update after you go back.  Can you add a GoBack call similar
to line 1713 below and verify we get the update?

[aelias_OOO_until_Jul13, 2017/01/12 21:19:13]

The previous version did fail without the fix, but I changed the test to more
specifically simulate the back button scenario.

+}
+
 // Tests what happens when we navigate back successfully
 TEST_F(NavigationControllerTest, Back) {
   NavigationControllerImpl& controller = controller_impl();
   TestNotificationTracker notifications;
   RegisterForAllNavNotifications(&notifications, &controller);
 
   const GURL url1("http://foo1");
   main_test_rfh()->NavigateAndCommitRendererInitiated(true, url1);
   EXPECT_EQ(1U, navigation_entry_committed_counter_);
   navigation_entry_committed_counter_ = 0;
@@ skipping 3629 matching lines @@
   main_test_rfh()->SimulateNavigationStart(url_1);
   EXPECT_EQ(url_1, controller.GetVisibleEntry()->GetURL());
   EXPECT_EQ(ReloadType::NONE, last_reload_type_);
 
   main_test_rfh()->SimulateNavigationCommit(url_2);
   main_test_rfh()->SimulateNavigationCommit(url_1);
   main_test_rfh()->SimulateNavigationCommit(url_1);
 }
 
 }  // namespace content