[unit] log browser output

Bug: none
Change-Id: I8aabb82379cabe1939e05a55d04cc61d715b2c21
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6387802
Commit-Queue: Simon Zünd <[email protected]>
Auto-Submit: Philip Pfaffe <[email protected]>
Reviewed-by: Simon Zünd <[email protected]>
Commit-Queue: Philip Pfaffe <[email protected]>

Author: pfaffe

test/unit/karma.conf.ts

@@ -41,6 +41,7 @@ const CustomChrome = function(this: any, _baseBrowserDecorator: unknown, args: B
       headless: !TestConfig.debug || TestConfig.headless,
       executablePath: TestConfig.chromeBinary,
       defaultViewport: null,
+      dumpio: true,
       args,
       ignoreDefaultArgs: ['--hide-scrollbars'],
     });