This adds `{Page,Frame}.isChecked(selector)` and `ElementHandle.isChecked()` methods.
Useful to do assertions in tests:
```js
await page.click('text="Add TODO"');
expect(await page.isChecked('.item-done')).toBe(false);
```
These methods are useful for verification in tests, e.g.
```js
expect(await page.isEnabled(':text("Remove All")')).toBe(false);
await page.click(':text("Add Item")');
expect(await page.isVisible('.item:text("new item")')).toBe(true);
expect(await page.isEnabled(':text("Remove All")')).toBe(true);
```
- This leaves just `recordVideos` and `videoSize` options on the context.
- Videos are saved to `artifactsPath`. We also save their ids to trace.
- `context.close()` waits for the processed videos.
api(trace): introduce artifacts options
This introduces launch({ artifactsPath }) and newContext({ relativeArtifactsPath, recordTrace }) options.
- artifactsPath option controls the directory where all artifacts go. If not passed, artifacts are not collected.
- relativeArtifactsPath can be used to put context-specific artifacts into a subfolder. If not passed, shared artifactsPath is used.
- recordTrace controls trace recording.
We also expose trace types under playwright/types/trace.d.ts.
In the follow up:
- videos will be put into artifactsPath;
- downloads will be put into artifactsPath, or keep using existing downloadsPath when artifactsPath is not specified.
This is a large rework of selectors:
- Each BrowserContext now has a separate Selectors instance that has its own registrations.
Most of them share a single sharedSelectors instance, but contexts created for a connected
browser have their own instance.
- Connected browser now gets a RemoteBrowser object that encapsulates Selectors and Browser.
This Selectors object is registered with the api selectors.
- Public selectors.register api iterates over all registered Selectors channels
and registers in each of them.
- createSelector testing method migrated to ElementHandle._createSelectorForTest.
