Change some desktop notifications layout parameters to be per-platform rather...

chrome/browser/notifications/balloon_collection_mac.mm

 // Copyright (c) 2009 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/balloon_collection.h"
 #include "chrome/browser/cocoa/notifications/balloon_view_bridge.h"
 
 #include "base/logging.h"
 
 Balloon* BalloonCollectionImpl::MakeBalloon(const Notification& notification,
                                             Profile* profile) {
   Balloon* balloon = new Balloon(notification, profile, this);
   balloon->set_view(new BalloonViewBridge());
   gfx::Size size(layout_.min_balloon_width(), layout_.min_balloon_height());
   balloon->set_content_size(size);
   return balloon;
 }
 
+int BalloonCollectionImpl::Layout::InterBalloonMargin() const {
+  return 5;
+}
+
+int BalloonCollectionImpl::Layout::HorizontalEdgeMargin() const {
+  return 5;
+}
+
+int BalloonCollectionImpl::Layout::VerticalEdgeMargin() const {
+  return 18;
+}