Request the icon of a Web Notification in the renderer process.

chrome/browser/notifications/desktop_notification_service.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/notifications/desktop_notification_service.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 139 matching lines @@
     content::RenderFrameHost* render_frame_host,
     scoped_ptr<content::DesktopNotificationDelegate> delegate,
     base::Closure* cancel_callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   const GURL& origin = params.origin;
   NotificationObjectProxy* proxy =
       new NotificationObjectProxy(render_frame_host, delegate.Pass());
 
   base::string16 display_source = DisplayNameForOriginInProcessId(
       origin, render_frame_host->GetProcess()->GetID());
-  Notification notification(origin, params.icon_url, params.title,
-      params.body, params.direction, display_source, params.replace_id,
-      proxy);
+
+  Notification notification(origin,
+                            gfx::Image::CreateFrom1xBitmap(params.icon),

[dewittj, 2014/09/17 16:36:20]

I think that today, this will work for 1x and 2x displays as we've written the
views code but it is still risky; since the image will be marked as having only
a 1x representation.

I realize that this is a limitation of the current API, but possibly good to put
a TODO in here, to fix the image creation someday.

[Jun Mukai, 2014/09/17 16:57:47]

Using CreateFrom1xBitmap is not bad by itself, it will automatically rescaled in
Views size IIRC.  However, that means the scale could be blurry in some
situation, and specifying larger image for hidpi device may cause weird effect
of rescaling and shrinking (I haven't checked it though).

More thinking deeply, specifying single bitmap itself could be a bad idea by
itself because we have no idea what is the best image in some environment, like
Retina Macbook or Chromebook Pixel with normal external display -- the
notification card appears on both screens. But to address that issue, we need to
change the notification API to support such situation.

Until then, it would be good to put a TODO here.

[Peter Beverloo, 2014/09/18 16:54:37]

I agree that it would be good for the Notification API to support images of
different resolution (there's Android devices with 3x density out there), and
will pursue this for the HTML5 API.

I've added a TODO here for now.

+                            params.title,
+                            params.body,
+                            params.direction,
+                            display_source,
+                            params.replace_id,
+                            proxy);
 
   // The webkit notification doesn't timeout.
   notification.set_never_timeout(true);
 
   g_browser_process->notification_ui_manager()->Add(notification, profile_);
   if (cancel_callback)
     *cancel_callback = base::Bind(&CancelNotification, proxy->id());
 
   DesktopNotificationProfileUtil::UsePermission(profile_, origin);
 }
@@ skipping 162 matching lines @@
   // Tell the IO thread that this extension's permission for notifications
   // has changed.
   extensions::InfoMap* extension_info_map =
       extensions::ExtensionSystem::Get(profile_)->info_map();
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&extensions::InfoMap::SetNotificationsDisabled,
                  extension_info_map, notifier_id.id, !enabled));
 #endif
 }