Remove the extension uninstall dialog black border.

ExtensionUninstallDialogViews uses Widget::CreateWindow. 
Use DialogDelegate::CreateDialogWidget instead. 
See before/after pics at http://crbug.com/166075#c95
Trigger the dialog by clicking a trash icon at about:extensions

BUG=166075
TEST=Extension uninstall shortcut dialog does not have a black border. 
R=sky@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15932002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@201995 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/extensions/extension_uninstall_dialog_view.cc

@@ -147,7 +147,7 @@ void ExtensionUninstallDialogViews::Show() {
   }
 
   view_ = new ExtensionUninstallDialogDelegateView(this, extension_, &icon_);
-  views::Widget::CreateWindowWithParent(view_, parent)->Show();
+  views::DialogDelegate::CreateDialogWidget(view_, NULL, parent)->Show();
 }
 
 void ExtensionUninstallDialogViews::ExtensionUninstallAccepted() {