Add border radius to merge editor button (microsoft#158508)

Author: Miguel Solorio

src/vs/workbench/browser/codeeditor.ts

@@ -153,6 +153,7 @@ export class FloatingClickWidget extends Widget implements IOverlayWidget {
 
 		this._domNode = $('.floating-click-widget');
 		this._domNode.style.padding = '6px 11px';
+		this._domNode.style.borderRadius = '2px';
 		this._domNode.style.cursor = 'pointer';
 
 		if (keyBindingAction) {