[Mac] Delete old balloon and Notification Center notification implementations.

chrome/browser/ui/cocoa/notifications/balloon_view_host_mac.mm

-// 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/ui/cocoa/notifications/balloon_view_host_mac.h"
-
-#import <Cocoa/Cocoa.h>
-
-#include "content/public/browser/render_view_host.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_view.h"
-
-BalloonViewHost::BalloonViewHost(Balloon* balloon)
-    : BalloonHost(balloon) {
-}
-
-BalloonViewHost::~BalloonViewHost() {
-   Shutdown();
-}
-
-void BalloonViewHost::UpdateActualSize(const gfx::Size& new_size) {
-  web_contents_->GetView()->SizeContents(new_size);
-  NSView* view = native_view();
-  NSRect frame = [view frame];
-  frame.size.width = new_size.width();
-  frame.size.height = new_size.height();
-
-  [view setFrame:frame];
-  [view setNeedsDisplay:YES];
-}
-
-gfx::NativeView BalloonViewHost::native_view() const {
-  return web_contents_->GetView()->GetContentNativeView();
-}