Extract some account chooser views things for cross-platform use.

chrome/browser/ui/passwords/account_avatar_fetcher.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/ui/passwords/account_avatar_fetcher.h"
+
+#include "net/base/load_flags.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/image/image_skia_operations.h"
+
+AccountAvatarFetcher::AccountAvatarFetcher(
+    const GURL& url,
+    const base::WeakPtr<AccountAvatarFetcherDelegate>& delegate)
+    : fetcher_(url, this), delegate_(delegate) {
+}
+
+AccountAvatarFetcher::~AccountAvatarFetcher() = default;
+
+void AccountAvatarFetcher::Start(
+    net::URLRequestContextGetter* request_context) {
+  fetcher_.Start(request_context, std::string(),
+                 net::URLRequest::NEVER_CLEAR_REFERRER,
+                 net::LOAD_DO_NOT_SEND_COOKIES | net::LOAD_DO_NOT_SAVE_COOKIES |
+                     net::LOAD_MAYBE_USER_GESTURE);
+}
+
+void AccountAvatarFetcher::OnFetchComplete(const GURL /*url*/,
+                                           const SkBitmap* bitmap) {
+  if (bitmap && delegate_)
+    delegate_->UpdateAvatar(gfx::ImageSkia::CreateFrom1xBitmap(*bitmap));
+
+  delete this;
+}