src/vs/workbench/contrib/webviewPanel/browser/webviewEditor.ts/WebviewEditor/claimWebview
class WebviewEditor:	private claimWebview(input: WebviewInput): void {
		input.webview.claim(this, this.scopedContextKeyService);

		if (this._element) {
			this._element.setAttribute('aria-flowto', input.webview.container.id);
			DOM.setParentFlowTo(input.webview.container, this._element);
		}

		this._webviewVisibleDisposables.clear();

		// Webviews are not part of the normal editor dom, so we have to register our own drag and drop handler on them.
		this._webviewVisibleDisposables.add(this._editorDropService.createEditorDropTarget(input.webview.container, {
			containsGroup: (group) => this.group?.id === group.id
		}));

		this._webviewVisibleDisposables.add(new WebviewWindowDragMonitor(() => this.webview));

		this.synchronizeWebviewContainerDimensions(input.webview);
		this._webviewVisibleDisposables.add(this.trackFocus(input.webview));
	}