[Extensions] Make Event::restrict_to_browser_context const.

chrome/browser/extensions/api/downloads/downloads_api.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/downloads/downloads_api.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <memory>
 #include <set>
@@ skipping 1868 matching lines @@
     bool include_incognito,
     const Event::WillDispatchCallback& will_dispatch_callback,
     std::unique_ptr<base::Value> arg) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (!EventRouter::Get(profile_))
     return;
   std::unique_ptr<base::ListValue> args(new base::ListValue());
   args->Append(std::move(arg));
   std::string json_args;
   base::JSONWriter::Write(*args, &json_args);
-  std::unique_ptr<Event> event(
-      new Event(histogram_value, event_name, std::move(args)));
   // The downloads system wants to share on-record events with off-record
   // extension renderers even in incognito_split_mode because that's how
   // chrome://downloads works. The "restrict_to_profile" mechanism does not
   // anticipate this, so it does not automatically prevent sharing off-record
   // events with on-record extension renderers.

[Devlin, 2017/05/24 16:08:18]

This makes sense (at least, somewhat), but it's still the wrong granularity. 
Instead, we should introduce something like "include incognito" in the event
structure to handle this case, because otherwise this will broadcast to
unrelated profiles.  Can we add a TODO?

[lazyboy, 2017/05/24 19:19:32]

Added a crbug. Added TODO here and in Event constructor.

-  event->restrict_to_browser_context =
+  Profile* restrict_to_browser_context =
       (include_incognito && !profile_->IsOffTheRecord()) ? NULL : profile_;
+  auto event =
+      base::MakeUnique<Event>(histogram_value, event_name, std::move(args),
+                              restrict_to_browser_context);
   event->will_dispatch_callback = will_dispatch_callback;
   EventRouter::Get(profile_)->BroadcastEvent(std::move(event));
   DownloadsNotificationSource notification_source;
   notification_source.event_name = event_name;
   notification_source.profile = profile_;
   content::Source<DownloadsNotificationSource> content_source(
       &notification_source);
   content::NotificationService::current()->Notify(
       extensions::NOTIFICATION_EXTENSION_DOWNLOADS_EVENT,
       content_source,
@@ skipping 18 matching lines @@
     return;
   base::Time now(base::Time::Now());
   int delta = now.ToTimeT() - last_checked_removal_.ToTimeT();
   if (delta <= kFileExistenceRateLimitSeconds)
     return;
   last_checked_removal_ = now;
   manager->CheckForHistoryFilesRemoval();
 }
 
 }  // namespace extensions