Removing support for timeline perf logging preference in .NET ChromeD…

…river

According to chromedriver bug #2034
(https://bugs.chromium.org/p/chromedriver/issues/detail?id=2034),
the enableTimeline performance logging preference is no longer accespted
by chromedriver.exe. The .NET language bindings will no longer send that
preference to the driver executable. Additionally, the peroperty setting
the preference has been deprecated, and will generate a compile-time
warning. The property will be remvoed in a future release. Fixes
issue #5481.

dotnet/src/webdriver/Chrome/ChromeOptions.cs

@@ -639,7 +639,6 @@ private Dictionary<string, object> GeneratePerformanceLoggingPreferencesDictiona
             Dictionary<string, object> perfLoggingPrefsDictionary = new Dictionary<string, object>();
             perfLoggingPrefsDictionary["enableNetwork"] = this.perfLoggingPreferences.IsCollectingNetworkEvents;
             perfLoggingPrefsDictionary["enablePage"] = this.perfLoggingPreferences.IsCollectingPageEvents;
-            perfLoggingPrefsDictionary["enableTimeline"] = this.perfLoggingPreferences.IsCollectingTimelineEvents;
 
             string tracingCategories = this.perfLoggingPreferences.TracingCategories;
             if (!string.IsNullOrEmpty(tracingCategories))

dotnet/src/webdriver/Chrome/ChromePerformanceLoggingPreferences.cs

@@ -1,4 +1,4 @@
-// <copyright file="ChromePerformanceLoggingPreferences.cs" company="WebDriver Committers">
+// <copyright file="ChromePerformanceLoggingPreferences.cs" company="WebDriver Committers">
 // Licensed to the Software Freedom Conservancy (SFC) under one
 // or more contributor license agreements. See the NOTICE file
 // distributed with this work for additional information
@@ -58,6 +58,7 @@ public bool IsCollectingPageEvents
         /// Defaults to <see langword="true"/>, but is set to <see langword="false"/> when tracing
         /// is enabled by adding one or more tracing categories.
         /// </summary>
+        [Obsolete("Setting 'enableTimeline is no longer supported by chromedriver. This preference will no longer be sent to chromedriver. This property will be removed in a future release.")]
         public bool IsCollectingTimelineEvents
         {
             get { return this.isCollectingTimelineEvents; }