Adding support for .NET legacy log API for drivers that support them

The logging APIs (`driver.Manage().Logs`) are not part of the W3C
WebDriver Specification, and users should only use them for drivers
that support the extension end points for the methods. Drivers that
support these methods will be marked with the new ISupportsLogs
interface, and the user can use a cast (using a non-throwing operator
like the `is` or the `as` operator) to check whether the API is
supported before attempting to call the logging methods. If the
driver does not implement the interface, the logging methods will
not throw (for now), but will return empty lists instead of valid
data.

dotnet/src/webdriver/Chromium/ChromiumDriver.cs

@@ -22,7 +22,7 @@
 
 namespace OpenQA.Selenium.Chromium
 {
-    public abstract class ChromiumDriver : RemoteWebDriver
+    public abstract class ChromiumDriver : RemoteWebDriver, ISupportsLogs
     {
         /// <summary>
         /// Accept untrusted SSL Certificates

dotnet/src/webdriver/ISupportsLogs.cs

@@ -0,0 +1,34 @@
+// <copyright file="ISupportsLogs.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
+// regarding copyright ownership. The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace OpenQA.Selenium
+{
+    /// <summary>
+    /// Marker interface indicating that an object implementing
+    /// the interface supports the legacy log retrieval methods.
+    /// </summary>
+    public interface ISupportsLogs
+    {
+    }
+}

dotnet/src/webdriver/Remote/RemoteLogs.cs

@@ -27,6 +27,7 @@ namespace OpenQA.Selenium.Remote
     public class RemoteLogs : ILogs
     {
         private RemoteWebDriver driver;
+        private bool isLogSupported = false;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="RemoteLogs"/> class.
@@ -35,6 +36,7 @@ public class RemoteLogs : ILogs
         public RemoteLogs(RemoteWebDriver driver)
         {
             this.driver = driver;
+            this.isLogSupported = (this.driver as ISupportsLogs) != null;
         }
 
         /// <summary>
@@ -45,6 +47,19 @@ public ReadOnlyCollection<string> AvailableLogTypes
             get
             {
                 List<string> availableLogTypes = new List<string>();
+                if (this.isLogSupported)
+                {
+                    Response commandResponse = this.driver.InternalExecute(DriverCommand.GetAvailableLogTypes, null);
+                    object[] responseValue = commandResponse.Value as object[];
+                    if (responseValue != null)
+                    {
+                        foreach (object logKind in responseValue)
+                        {
+                            availableLogTypes.Add(logKind.ToString());
+                        }
+                    }
+                }
+
                 return availableLogTypes.AsReadOnly();
             }
         }
@@ -58,6 +73,26 @@ public ReadOnlyCollection<string> AvailableLogTypes
         public ReadOnlyCollection<LogEntry> GetLog(string logKind)
         {
             List<LogEntry> entries = new List<LogEntry>();
+            if (this.isLogSupported)
+            {
+                Dictionary<string, object> parameters = new Dictionary<string, object>();
+                parameters.Add("type", logKind);
+                Response commandResponse = this.driver.InternalExecute(DriverCommand.GetLog, parameters);
+
+                object[] responseValue = commandResponse.Value as object[];
+                if (responseValue != null)
+                {
+                    foreach (object rawEntry in responseValue)
+                    {
+                        Dictionary<string, object> entryDictionary = rawEntry as Dictionary<string, object>;
+                        if (entryDictionary != null)
+                        {
+                            entries.Add(LogEntry.FromDictionary(entryDictionary));
+                        }
+                    }
+                }
+            }
+
             return entries.AsReadOnly();
         }
     }

dotnet/src/webdriver/Remote/RemoteWebDriver.cs

@@ -166,6 +166,15 @@ public RemoteWebDriver(ICommandExecutor commandExecutor, ICapabilities desiredCa
                     this.storage = new RemoteWebStorage(this);
                 }
             }
+
+            if ((this as ISupportsLogs) != null)
+            {
+                // Only add the legacy log commands if the driver supports
+                // retrieving the logs via the extension end points.
+                this.CommandExecutor.CommandInfoRepository.TryAddCommand(DriverCommand.GetAvailableLogTypes, new CommandInfo(CommandInfo.GetCommand, "/session/{sessionId}/se/log/types"));
+                this.CommandExecutor.CommandInfoRepository.TryAddCommand(DriverCommand.GetLog, new CommandInfo(CommandInfo.GetCommand, "/session/{sessionId}/se/logs"));
+            }
+
         }
 
         /// <summary>