Refactored-out the code of thumbnaling algorithm from thumbnail_tab_helper.

chrome/browser/thumbnails/thumbnailing_context.cc

+// Copyright (c) 2013 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/thumbnails/thumbnailing_context.h"
+
+#include "content/public/browser/render_view_host.h"
+
+namespace thumbnails {
+
+ThumbnailingContext::ThumbnailingContext(content::WebContents* web_contents,
+                                         ThumbnailService* receiving_service,
+                                         bool load_interrupted)
+    : service(receiving_service),
+      url(web_contents->GetURL()),
+      clip_result(CLIP_RESULT_UNPROCESSED) {
+  score.at_top =
+      (web_contents->GetRenderViewHost()->GetLastScrollOffset().y() == 0);
+  score.load_completed = !web_contents->IsLoading() && !load_interrupted;
+}
+
+ThumbnailingContext::~ThumbnailingContext() {
+}
+
+}