Basic DragImage implementation....

chrome/browser/extensions/extension_host.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/extensions/extension_host.h"
 
 #include <list>
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ skipping 539 matching lines @@
   // TODO(erikkay): These two lines could be refactored with TabContentsView.
   widget_host_view->InitAsPopup(render_view_host()->view(), initial_pos);
   widget_host_view->GetRenderWidgetHost()->Init();
 }
 
 void ExtensionHost::ShowContextMenu(const ContextMenuParams& params) {
   // TODO(erikkay) Show a default context menu.
 }
 
 void ExtensionHost::StartDragging(const WebDropData& drop_data,
-    WebDragOperationsMask operation_mask) {
+    WebDragOperationsMask operation_mask,
+    const SkBitmap& image,
+    const gfx::Point& image_offset) {
   // We're not going to do any drag & drop, but we have to tell the renderer the
   // drag & drop ended, othewise the renderer thinks the drag operation is
   // underway and mouse events won't work.  See bug 34061.
   // TODO(twiz) Implement drag & drop support for ExtensionHost instances.
   // See feature issue 36288.
   render_view_host()->DragSourceSystemDragEnded();
 }
 
 void ExtensionHost::UpdateDragCursor(WebDragOperation operation) {
 }
@@ skipping 129 matching lines @@
     // Extensions hosted in ExternalTabContainer objects may not have
     // an associated browser.
     Browser* browser = GetBrowser();
     if (browser)
       window_id = ExtensionTabUtil::GetWindowId(browser);
   } else if (extension_host_type_ != ViewType::EXTENSION_BACKGROUND_PAGE) {
     NOTREACHED();
   }
   return window_id;
 }