fix(tracing): Fix missing page load metrics in Electron renderer (#5187)

Electron renderers can have a combined Chrome and node.js context which can cause it to be detected as node.js when in fact it has full browser features.

This PR simplifies the detection of the browser performance API so that it doesn't fail to record page load metrics when running in an Electron renderer with mixed context.

Author: timfish

packages/tracing/src/browser/metrics/index.ts

@@ -1,6 +1,6 @@
 /* eslint-disable max-lines */
 import { Measurements } from '@sentry/types';
-import { browserPerformanceTimeOrigin, getGlobalObject, htmlTreeAsString, isNodeEnv, logger } from '@sentry/utils';
+import { browserPerformanceTimeOrigin, getGlobalObject, htmlTreeAsString, logger } from '@sentry/utils';
 
 import { IS_DEBUG_BUILD } from '../../flags';
 import { Transaction } from '../../transaction';
@@ -14,8 +14,8 @@ import { _startChild, isMeasurementValue } from './utils';
 
 const global = getGlobalObject<Window>();
 
-function getBrowserPerformanceAPI(): false | Performance {
-  return !isNodeEnv() && global && global.document && global.performance;
+function getBrowserPerformanceAPI(): Performance | undefined {
+  return global && global.addEventListener && global.performance;
 }
 
 let _performanceCursor: number = 0;