Remove TopSites::IsEnabled() as well as related dead code.

chrome/browser/dom_ui/dom_ui_thumbnail_source.cc

 // Copyright (c) 2010 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/dom_ui/dom_ui_thumbnail_source.h"
 
 #include "app/resource_bundle.h"
 #include "base/callback.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/common/url_constants.h"
 #include "googleurl/src/gurl.h"
 #include "grit/theme_resources.h"
 
 DOMUIThumbnailSource::DOMUIThumbnailSource(Profile* profile)
     : DataSource(chrome::kChromeUIThumbnailPath, MessageLoop::current()),
       profile_(profile) {
-  if (history::TopSites::IsEnabled()) {
-    // Set TopSites now as Profile isn't thread safe.
-    top_sites_ = profile_->GetTopSites();
-  }
+  // Set TopSites now as Profile isn't thread safe.
+  top_sites_ = profile_->GetTopSites();
 }
 
 DOMUIThumbnailSource::~DOMUIThumbnailSource() {
 }
 
 void DOMUIThumbnailSource::StartDataRequest(const std::string& path,
                                             bool is_off_the_record,
                                             int request_id) {
-  if (top_sites_.get()) {
-    scoped_refptr<RefCountedBytes> data;
-    if (top_sites_->GetPageThumbnail(GURL(path), &data)) {
-      // We have the thumbnail.
-      SendResponse(request_id, data.get());
-    } else {
-      SendDefaultThumbnail(request_id);
-    }
-    return;
-  }
-
-  HistoryService* hs = profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
-  if (hs) {
-    HistoryService::Handle handle = hs->GetPageThumbnail(
-        GURL(path),
-        &cancelable_consumer_,
-        NewCallback(this, &DOMUIThumbnailSource::OnThumbnailDataAvailable));
-    // Attach the ChromeURLDataManager request ID to the history request.
-    cancelable_consumer_.SetClientData(hs, handle, request_id);
+  scoped_refptr<RefCountedBytes> data;
+  if (top_sites_->GetPageThumbnail(GURL(path), &data)) {
+    // We have the thumbnail.
+    SendResponse(request_id, data.get());
   } else {
-    // Tell the caller that no thumbnail is available.
-    SendResponse(request_id, NULL);
+    SendDefaultThumbnail(request_id);
   }
 }
 
 std::string DOMUIThumbnailSource::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";
 }
 
 MessageLoop* DOMUIThumbnailSource::MessageLoopForRequestPath(
     const std::string& path) const {
   // TopSites can be accessed from the IO thread.
   return top_sites_.get() ? NULL : DataSource::MessageLoopForRequestPath(path);
 }
 
 void DOMUIThumbnailSource::SendDefaultThumbnail(int request_id) {
   // Use placeholder thumbnail.
   if (!default_thumbnail_.get()) {
     default_thumbnail_ =
         ResourceBundle::GetSharedInstance().LoadDataResourceBytes(
             IDR_DEFAULT_THUMBNAIL);
   }
   SendResponse(request_id, default_thumbnail_);
 }
-
-void DOMUIThumbnailSource::OnThumbnailDataAvailable(
-    HistoryService::Handle request_handle,
-    scoped_refptr<RefCountedBytes> data) {
-  int request_id = cancelable_consumer_.GetClientDataForCurrentRequest();
-  // Forward the data along to the networking system.
-  if (data.get() && !data->data.empty()) {
-    SendResponse(request_id, data);
-  } else {
-    SendDefaultThumbnail(request_id);
-  }
-}