fix(har): do not complain about a lot of listeners (microsoft#4675)

Author: pavelfeldman

docs-src/api-body.md

@@ -1405,7 +1405,7 @@ Shortcut for main frame's [frame.focus()]().
 ## method: Page.frame
 - returns: <[null]|[Frame]>
 
-Returns frame matching the criteria. Returns `null` if no frame matches.
+Returns frame matching the specified criteria. Either `name` or `url` must be specified.
 
 ```js
 const frame = page.frame('frame-name');
@@ -1415,8 +1415,6 @@ const frame = page.frame('frame-name');
 const frame = page.frame({ url: /.*domain.*/ });
 ```
 
-Returns frame matching the specified criteria. Either `name` or `url` must be specified.
-
 ### param: Page.frame.frameSelector
 - `frameSelector` <[string]|[Object]>
   - `name` <[string]> frame name specified in the `iframe`'s `name` attribute

docs/api.md

@@ -1608,7 +1608,7 @@ Shortcut for main frame's [frame.focus(selector[, options])](#framefocusselector
   - `url` <[string]|[RegExp]|[Function]> A glob pattern, regex pattern or predicate receiving frame's `url` as a [URL] object.
 - returns: <[null]|[Frame]>
 
-Returns frame matching the criteria. Returns `null` if no frame matches.
+Returns frame matching the specified criteria. Either `name` or `url` must be specified.
 
 ```js
 const frame = page.frame('frame-name');
@@ -1618,8 +1618,6 @@ const frame = page.frame('frame-name');
 const frame = page.frame({ url: /.*domain.*/ });
 ```
 
-Returns frame matching the specified criteria. Either `name` or `url` must be specified.
-
 #### page.frames()
 - returns: <[Array]<[Frame]>>
 

src/server/page.ts

@@ -149,6 +149,7 @@ export class Page extends EventEmitter {
 
   constructor(delegate: PageDelegate, browserContext: BrowserContext) {
     super();
+    this.setMaxListeners(0);
     this._delegate = delegate;
     this._closedCallback = () => {};
     this._closedPromise = new Promise(f => this._closedCallback = f);