Reload: "Request desktop site" feature should ask reposting

Now Android Chrome does not confirm if it is expected to repost a form
on selecting "Request desktop site".

This change modifies to ask it as we do in other cases.

If a user reject reposting, the navigation switches to use desktop user
agent strings as usuals, but only for the next navigation and
following ones.

BUG=675522
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2587923002
Cr-Commit-Position: refs/heads/master@{#439727}

content/browser/frame_host/navigation_controller_android.cc

@@ -340,8 +340,7 @@ void NavigationControllerAndroid::SetUseDesktopUserAgent(
   if (reload_on_state_change) {
     // Reloading the page will send the override down as part of the
     // navigation IPC message.
-    // TODO(toyoshim): Should this call use |true| for check_for_post argument?
-    navigation_controller_->Reload(ReloadType::ORIGINAL_REQUEST_URL, false);
+    navigation_controller_->Reload(ReloadType::ORIGINAL_REQUEST_URL, true);
   }
 }