Implement app banner info bars on desktop.

chrome/browser/banners/app_banner_manager_desktop.cc

+// Copyright 2015 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/banners/app_banner_manager_desktop.h"
+
+#include "chrome/browser/banners/app_banner_data_fetcher_desktop.h"
+#include "extensions/common/constants.h"
+
+namespace {
+// TODO(dominickn) Enforce the set of icons which will guarantee the best
+// user experience.
+int kMinimumIconSize = extension_misc::EXTENSION_ICON_LARGE;
+}  // anonymous namespace
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(banners::AppBannerManagerDesktop);
+
+namespace banners {
+
+AppBannerManagerDesktop::AppBannerManagerDesktop(

[benwells, 2015/06/03 06:13:55]

Nit: keep functions here in same order as in .h

[dominickn (DO NOT USE), 2015/06/03 07:10:36]

Done.

+    content::WebContents* web_contents)
+    : AppBannerManager(web_contents, kMinimumIconSize) {
+}
+
+AppBannerDataFetcher* AppBannerManagerDesktop::CreateAppBannerDataFetcher(
+    base::WeakPtr<AppBannerDataFetcher::Delegate> weak_delegate,
+    const int ideal_icon_size) {
+  return new AppBannerDataFetcherDesktop(web_contents(), weak_delegate,
+                                         ideal_icon_size);
+}
+
+}  // namespace banners