and can contain hierarchical content with disclosure arrows.
A lot of DataGrid was copied from treeoutline.js. This change
makes the database views use the DataGrid. It will later be
used by the ProfileView.

Reviewed by Adam Roben.

* page/inspector/DataGrid.js: Added. Most copied from treeoutline.js
and modified to work with table elements.
* page/inspector/DatabaseQueryView.js:
(WebInspector.DatabaseQueryView.prototype._queryFinished):
Call DatabasesPanel.dataGridForResult and adds the inline style to
the DataGrid element.
* page/inspector/DatabaseTableView.js:
(WebInspector.DatabaseTableView.prototype._queryFinished):
Call DatabasesPanel.dataGridForResult.
* page/inspector/DatabasesPanel.js:
(WebInspector.DatabasesPanel.prototype._tableForResult): Removed.
(WebInspector.DatabasesPanel.prototype.dataGridForResult): Added.
Similar to the previous _tableForResult function, but makes a DataGrid.
* page/inspector/inspector.css: Changes to the data-gr...