[Extensions] Make Event::restrict_to_browser_context const.

chrome/browser/extensions/api/tab_capture/tab_capture_registry.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 "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
@@ skipping 409 matching lines @@
     return;
 
   EventRouter* router = EventRouter::Get(browser_context_);
   if (!router)
     return;
 
   std::unique_ptr<base::ListValue> args(new base::ListValue());
   tab_capture::CaptureInfo info;
   request->GetCaptureInfo(&info);
   args->Append(info.ToValue());
-  std::unique_ptr<Event> event(
-      new Event(events::TAB_CAPTURE_ON_STATUS_CHANGED,
-                tab_capture::OnStatusChanged::kEventName, std::move(args)));
-  event->restrict_to_browser_context = browser_context_;
+  auto event = base::MakeUnique<Event>(events::TAB_CAPTURE_ON_STATUS_CHANGED,
+                                       tab_capture::OnStatusChanged::kEventName,
+                                       std::move(args), browser_context_);
 
   router->DispatchEventToExtension(request->extension_id(), std::move(event));
 }
 
 TabCaptureRegistry::LiveRequest* TabCaptureRegistry::FindRequest(
     const content::WebContents* target_contents) const {
   for (const auto& request : requests_) {
     if (request->web_contents() == target_contents)
       return request.get();
   }
@@ skipping 19 matching lines @@
        it != requests_.end(); ++it) {
     if (it->get() == request) {
       requests_.erase(it);
       return;
     }
   }
   NOTREACHED();
 }
 
 }  // namespace extensions