Revert of NTP Zombie Code Slayer Part IV: Most Visited

chrome/browser/ui/webui/ntp/thumbnail_source.cc

+// 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/webui/ntp/thumbnail_source.h"
+
+#include "base/callback.h"
+#include "base/memory/ref_counted_memory.h"
+#include "base/message_loop/message_loop.h"
+#include "chrome/browser/search/instant_io_context.h"
+#include "chrome/browser/thumbnails/thumbnail_service.h"
+#include "chrome/browser/thumbnails/thumbnail_service_factory.h"
+#include "chrome/common/url_constants.h"
+#include "net/url_request/url_request.h"
+#include "url/gurl.h"
+
+// Set ThumbnailService now as Profile isn't thread safe.
+ThumbnailSource::ThumbnailSource(Profile* profile, bool capture_thumbnails)
+    : thumbnail_service_(ThumbnailServiceFactory::GetForProfile(profile)),
+      capture_thumbnails_(capture_thumbnails) {
+}
+
+ThumbnailSource::~ThumbnailSource() {
+}
+
+std::string ThumbnailSource::GetSource() const {
+  return capture_thumbnails_ ?
+      chrome::kChromeUIThumbnailHost2 : chrome::kChromeUIThumbnailHost;
+}
+
+void ThumbnailSource::StartDataRequest(
+    const std::string& path,
+    int render_process_id,
+    int render_frame_id,
+    const content::URLDataSource::GotDataCallback& callback) {
+  scoped_refptr<base::RefCountedMemory> data;
+  if (thumbnail_service_->GetPageThumbnail(GURL(path), capture_thumbnails_,
+                                           &data)) {
+    // We have the thumbnail.
+    callback.Run(data.get());
+  } else {
+    callback.Run(default_thumbnail_.get());
+  }
+  if (capture_thumbnails_)
+    thumbnail_service_->AddForcedURL(GURL(path));
+}
+
+std::string ThumbnailSource::GetMimeType(const std::string&) const {
+  // We need to explicitly return a mime type, otherwise if the user tries to
+  // drag the image they get no extension.
+  return "image/png";
+}
+
+base::MessageLoop* ThumbnailSource::MessageLoopForRequestPath(
+    const std::string& path) const {
+  // TopSites can be accessed from the IO thread.
+  return thumbnail_service_.get() ?
+      NULL : content::URLDataSource::MessageLoopForRequestPath(path);
+}
+
+bool ThumbnailSource::ShouldServiceRequest(
+    const net::URLRequest* request) const {
+  if (request->url().SchemeIs(chrome::kChromeSearchScheme))
+    return InstantIOContext::ShouldServiceRequest(request);
+  return URLDataSource::ShouldServiceRequest(request);
+}