Selenium: How to launch chrome with performance logging .net

[nessou]

Meta -

OS: Windows 7
Selenium Version: 2.53.0 .net
Browser: Google Chrome
Browser Version: 49.0.2623.87 (64 bits)

Expected Behavior -

Start Chrome driver using the option "PerformanceLoggingPreferences" to collect events from Network domain

Actual Behavior -

I am trying to launch Chrome using the option "PerformanceLoggingPreferences" but i got this error :
unknown error: perfLoggingPrefs specified, but performance logging was not enabled

Did i forgot something ? I can't find any examples with Chrome performance in .net.
This is a only way to collect network event in Chrome with webdriver ?

Steps to reproduce -

ChromePerformanceLoggingPreferences perfLogPrefs = new ChromePerformanceLoggingPreferences();
ChromeOptions options = new ChromeOptions();
perfLogPrefs.AddTracingCategories(new string[] { "devtools.timeline" });
options.PerformanceLoggingPreferences = perfLogPrefs;
options.AddAdditionalCapability(CapabilityType.EnableProfiling, true, true);
IWebDriver driver = new ChromeDriver(options);`

Thank you !.

[jimevans]

Your code is incomplete. As shown in the performance enhancement example for ChromeDriver, you need to enable specific logging preferences for performance. Your code should look like the following:

ChromePerformanceLoggingPreferences perfLogPrefs = new ChromePerformanceLoggingPreferences();
perfLogPrefs.AddTracingCategories(new string[] { "devtools.timeline" });

ChromeOptions options = new ChromeOptions();
options.PerformanceLoggingPreferences = perfLogPrefs;
// Note there is not yet a constant for "performance" as there is for other
// log types (e.g. LogType.Client), since Chrome is the only implementer
// for "performance".
options.SetLoggingPreference("performance", LogLevel.All);
IWebDriver driver = new ChromeDriver(options);`

[jhornych]

Was this answer tested? When I do copy the code above I do get this exception.

unknown error: cannot parse capability: goog:chromeOptions
from unknown error: cannot parse perfLoggingPrefs
from unknown error: unrecognized performance logging option: enableTimeline
(Driver info: chromedriver=2.35.528161,
platform=Windows NT 10.0.16299 x86_64)