desktopCapturer can be used in both main process and renderer process

* Fix custom scheme not registered as service worker scheme

* ServiceWorker loaders do not have WebContents associated

* Add test for service worker

* Revert "Fix custom scheme not registered as service worker scheme"

This reverts commit a249235b220a0edcfcb906e0b3b3c0486ece73a6.

* Add scheme to ServiceWorkerSchemes

fix: Fix main.js source code, missing large bracket

* docs: update Node global symbols example to use contextBridge

* Trigger Build

* docs: change Node API example to show how to expose a crypto API

Co-authored-by: Jeremy Rose <nornagon@nornagon.net>

* docs: Fix lint warning for crypto code sample

* docs: update node API example description to emphasize APIs instead of symbols

Co-authored-by: Jeremy Rose <nornagon@nornagon.net>

* test: spellchecker may take several minutes to load under ASan

* Add TODO for the timeout

* chore: rename process.contextIsolation to process.contextIsolated

* thing

desktopCapture.getSources() returns a promise which should resolve
when capturing finishes. Internally it creates an instance of
DesktopCapturer which is responsible for resolving or rejecting
the promise.

Between the time DesktopCapturer starts capturing frames and when
it finishes, it's possible for its handle to be GC'd leading to
it never resolving.

These changes pin the instance of DesktopCapturer until it either
finishes or errors.

fixes #25595

See https://github.com/SeleniumHQ/selenium/issues/9286
The existing snippet works with selenium-webdriver <= 3.6.0, but any more recent version seems to require using 'goog:chromeOptions' and forBrowser('chrome').

* docs: Update Quick Start Guide for Electron 12

With `contextIsolation` enabled by default in Electron 12, the Getting Started Guide no longer works as it is written. In order for the basic example to display values from `process.versions`, we need to add a `preload.js` to the example.

* fix: annotate preload code block with a language

* docs: update quick-start Fiddle example to use preload to provide version info

* fix: ensure example files end in a newline

* docs: add security warning to instructions for turning off contextIsolation

Co-authored-by: John Kleinschmidt <jkleinsc@github.com>

* docs: treat preload as an adjective instead of a noun

Co-authored-by: John Kleinschmidt <jkleinsc@github.com>

Co-authored-by: John Kleinschmidt <jkleinsc@github.com>

* test: running child app under ASan might receive SIGKILL

* test: renderer process of webview might receive SIGKILL under ASan

* test: increase timeout for asan build

* fix: recalibrate simpleFullscreen when display metrics change

* Address review feedback

* fix: compilation issues

* Address feedback from review

Fixes #28178

This reverts commit 01a2e231.

* docs: remove unnecessary enableBlinkFeatures

* docs: remove trailing comma

* docs: expand OS version prompt in issue template

* Update bug_report.yml

* fix: handle a nil backgroundColor in win.getBackgroundColor()

* spec: add crash case

* fix: update to fix native_views transparent color

* chore: fix lint