[Extensions] Make Event::restrict_to_browser_context const.

chrome/browser/extensions/api/automation_internal/automation_event_router.cc

 // Copyright 2015 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/extensions/api/automation_internal/automation_event_router.h"
 
 #include <algorithm>
 #include <memory>
 #include <string>
 #include <utility>
@@ skipping 98 matching lines @@
 
 void AutomationEventRouter::DispatchTreeDestroyedEvent(
     int tree_id,
     content::BrowserContext* browser_context) {
   if (listeners_.empty())
     return;
 
   browser_context = browser_context ? browser_context : active_profile_;
   std::unique_ptr<base::ListValue> args(
       api::automation_internal::OnAccessibilityTreeDestroyed::Create(tree_id));
-  std::unique_ptr<Event> event(new Event(
+  auto event = base::MakeUnique<Event>(
       events::AUTOMATION_INTERNAL_ON_ACCESSIBILITY_TREE_DESTROYED,
       api::automation_internal::OnAccessibilityTreeDestroyed::kEventName,
-      std::move(args)));
-  event->restrict_to_browser_context = browser_context;
+      std::move(args), browser_context);
   EventRouter::Get(browser_context)->BroadcastEvent(std::move(event));
 }
 
 AutomationEventRouter::AutomationListener::AutomationListener() {
 }
 
 AutomationEventRouter::AutomationListener::AutomationListener(
     const AutomationListener& other) = default;
 
 AutomationEventRouter::AutomationListener::~AutomationListener() {
@@ skipping 76 matching lines @@
     // only mark one as active.
     listener.is_active_profile = (extension_id_count == 1 ||
                                   rph->GetBrowserContext() == active_profile_);
 #else
     listener.is_active_profile = true;
 #endif
   }
 }
 
 }  // namespace extensions