Don't convert json edit data tostring

src/vs/workbench/api/common/extHostWebview.ts

@@ -243,7 +243,7 @@ export class ExtHostWebviewEditor extends Disposable implements vscode.WebviewPa
 		this._capabilities = capabilities;
 		if (capabilities.editingCapability) {
 			this._register(capabilities.editingCapability.onEdit(edit => {
-				this._proxy.$onEdit(this._handle, JSON.stringify(edit));
+				this._proxy.$onEdit(this._handle, edit);
 			}));
 		}
 	}