feat: promisify webContents.printToPDF() (#16795)

docs/api/promisification.md

@@ -28,17 +28,16 @@ When a majority of affected functions are migrated, this flag will be enabled by
 - [ses.clearAuthCache(options[, callback])](https://github.com/electron/electron/blob/master/docs/api/session.md#clearAuthCache)
 - [contents.executeJavaScript(code[, userGesture, callback])](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#executeJavaScript)
 - [contents.print([options], [callback])](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#print)
-- [contents.printToPDF(options, callback)](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#printToPDF)
 - [contents.savePage(fullPath, saveType, callback)](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#savePage)
 - [webFrame.executeJavaScript(code[, userGesture, callback])](https://github.com/electron/electron/blob/master/docs/api/web-frame.md#executeJavaScript)
 - [webFrame.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture, callback])](https://github.com/electron/electron/blob/master/docs/api/web-frame.md#executeJavaScriptInIsolatedWorld)
 - [webviewTag.executeJavaScript(code[, userGesture, callback])](https://github.com/electron/electron/blob/master/docs/api/webview-tag.md#executeJavaScript)
-- [webviewTag.printToPDF(options, callback)](https://github.com/electron/electron/blob/master/docs/api/webview-tag.md#printToPDF)
 
 ### Converted Functions
 
 - [app.getFileIcon(path[, options], callback)](https://github.com/electron/electron/blob/master/docs/api/app.md#getFileIcon)
 - [contents.capturePage([rect, ]callback)](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#capturePage)
+- [contents.printToPDF(options, callback)](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#printToPDF)
 - [contentTracing.getCategories(callback)](https://github.com/electron/electron/blob/master/docs/api/content-tracing.md#getCategories)
 - [contentTracing.startRecording(options, callback)](https://github.com/electron/electron/blob/master/docs/api/content-tracing.md#startRecording)
 - [contentTracing.stopRecording(resultFilePath, callback)](https://github.com/electron/electron/blob/master/docs/api/content-tracing.md#stopRecording)
@@ -50,5 +49,6 @@ When a majority of affected functions are migrated, this flag will be enabled by
 - [protocol.isProtocolHandled(scheme, callback)](https://github.com/electron/electron/blob/master/docs/api/protocol.md#isProtocolHandled)
 - [shell.openExternal(url[, options, callback])](https://github.com/electron/electron/blob/master/docs/api/shell.md#openExternal)
 - [webviewTag.capturePage([rect, ]callback)](https://github.com/electron/electron/blob/master/docs/api/webview-tag.md#capturePage)
+- [webviewTag.printToPDF(options, callback)](https://github.com/electron/electron/blob/master/docs/api/webview-tag.md#printToPDF)
 - [win.capturePage([rect, ]callback)](https://github.com/electron/electron/blob/master/docs/api/browser-window.md#capturePage)
 - [desktopCapturer.getSources(options, callback)](https://github.com/electron/electron/blob/master/docs/api/desktop-capturer.md#getSources)

docs/api/web-contents.md

@@ -1202,6 +1202,25 @@ settings.
 The `callback` will be called with `callback(error, data)` on completion. The
 `data` is a `Buffer` that contains the generated PDF data.
 
+**[Deprecated Soon](promisification.md)**
+
+#### `contents.printToPDF(options)`
+
+* `options` Object
+  * `marginsType` Integer (optional) - Specifies the type of margins to use. Uses 0 for
+    default margin, 1 for no margin, and 2 for minimum margin.
+  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
+    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
+    and `width` in microns.
+  * `printBackground` Boolean (optional) - Whether to print CSS backgrounds.
+  * `printSelectionOnly` Boolean (optional) - Whether to print selection only.
+  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.
+
+* Returns `Promise<Buffer>` - Resolves with the generated PDF data.
+
+Prints window's web page as PDF with Chromium's preview printing custom
+settings.
+
 The `landscape` will be ignored if `@page` CSS at-rule is used in the web page.
 
 By default, an empty `options` will be regarded as:

docs/api/webview-tag.md

@@ -542,6 +542,24 @@ Prints `webview`'s web page. Same as `webContents.print([options])`.
 
 Prints `webview`'s web page as PDF, Same as `webContents.printToPDF(options, callback)`.
 
+**[Deprecated Soon](promisification.md)**
+
+### `<webview>.printToPDF(options)`
+
+* `options` Object
+  * `marginsType` Integer (optional) - Specifies the type of margins to use. Uses 0 for
+    default margin, 1 for no margin, and 2 for minimum margin.
+  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
+    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
+    and `width` in microns.
+  * `printBackground` Boolean (optional) - Whether to print CSS backgrounds.
+  * `printSelectionOnly` Boolean (optional) - Whether to print selection only.
+  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.
+
+* Returns `Promise<Buffer>` - Resolves with the generated PDF data.
+
+Prints `webview`'s web page as PDF, Same as `webContents.printToPDF(options)`.
+
 ### `<webview>.capturePage([rect, ]callback)`
 
 * `rect` [Rectangle](structures/rectangle.md) (optional) - The bounds to capture