Ensure that Chrome is visible in the dialog by default

chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.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 "chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 311 matching lines @@
   if (HandleUrl(render_process_host_id, routing_id, url, handlers,
                 handlers.size(), &result)) {
     if (result == GetActionResult::HANDLE_URL_IN_ARC) {
       ArcNavigationThrottle::RecordUma(
           ArcNavigationThrottle::CloseReason::PREFERRED_ACTIVITY_FOUND,
           ArcNavigationThrottle::Platform::ARC);
     }
     return;  // the |url| has been handled.
   }
 
-  // Otherwise, retrieve icons of the activities.
+  // Otherwise, retrieve icons of the activities. First, swap |handler| elements
+  // to ensure Chrome is visible in the UI by default. Since this function is
+  // for handling external protocols, Chrome is rarely in the list, but if the
+  // |url| is intent: with fallback or geo:, for example, it may be.
+  std::pair<size_t, size_t> indices;
+  if (ArcNavigationThrottle::IsSwapElementsNeeded(handlers, &indices))
+    std::swap(handlers[indices.first], handlers[indices.second]);
+
+  // Then request the icons.
   std::vector<ActivityIconLoader::ActivityName> activities;
   for (const auto& handler : handlers) {
     activities.emplace_back(handler->package_name, handler->activity_name);
   }
   icon_loader->GetActivityIcons(
       activities, base::Bind(OnAppIconsReceived, render_process_host_id,
                              routing_id, url, base::Passed(&handlers)));
 }
 
 // Returns true if ARC should ignore the navigation with the |page_transition|.
@@ skipping 50 matching lines @@
 GetActionResult GetActionForTesting(
     const GURL& original_url,
     const mojo::Array<mojom::IntentHandlerInfoPtr>& handlers,
     size_t selected_app_index,
     std::pair<GURL, std::string>* out_url_and_package) {
   return GetAction(original_url, handlers, selected_app_index,
                    out_url_and_package);
 }
 
 }  // namespace arc