Dispose HttpRequestMessage and HttpResponseMessage objects when making a http call

Signed-off-by: Jim Evans <james.h.evans.jr@gmail.com>

Author: nvborisenko

dotnet/src/webdriver/Remote/HttpCommandExecutor.cs

@@ -193,7 +193,7 @@ public virtual Response Execute(Command commandToExecute)
                 string unknownErrorMessage = "An unknown exception was encountered sending an HTTP request to the remote WebDriver server for URL {0}. The exception message was: {1}";
                 throw new WebDriverException(string.Format(CultureInfo.InvariantCulture, unknownErrorMessage, requestInfo.FullUri.AbsoluteUri, ex.Message), ex);
             }
-            catch(TaskCanceledException ex)
+            catch (TaskCanceledException ex)
             {
                 string timeoutMessage = "The HTTP request to the remote WebDriver server for URL {0} timed out after {1} seconds.";
                 throw new WebDriverException(string.Format(CultureInfo.InvariantCulture, timeoutMessage, requestInfo.FullUri.AbsoluteUri, this.serverResponseTimeout.TotalSeconds), ex);
@@ -253,34 +253,39 @@ private async Task<HttpResponseInfo> MakeHttpRequest(HttpRequestInfo requestInfo
             this.OnSendingRemoteHttpRequest(eventArgs);
 
             HttpMethod method = new HttpMethod(requestInfo.HttpMethod);
-            HttpRequestMessage requestMessage = new HttpRequestMessage(method, requestInfo.FullUri);
-            if (requestInfo.HttpMethod == HttpCommandInfo.GetCommand)
+            using (HttpRequestMessage requestMessage = new HttpRequestMessage(method, requestInfo.FullUri))
             {
-                CacheControlHeaderValue cacheControlHeader = new CacheControlHeaderValue();
-                cacheControlHeader.NoCache = true;
-                requestMessage.Headers.CacheControl = cacheControlHeader;
-            }
+                if (requestInfo.HttpMethod == HttpCommandInfo.GetCommand)
+                {
+                    CacheControlHeaderValue cacheControlHeader = new CacheControlHeaderValue();
+                    cacheControlHeader.NoCache = true;
+                    requestMessage.Headers.CacheControl = cacheControlHeader;
+                }
 
-            if (requestInfo.HttpMethod == HttpCommandInfo.PostCommand)
-            {
-                MediaTypeWithQualityHeaderValue acceptHeader = new MediaTypeWithQualityHeaderValue(JsonMimeType);
-                acceptHeader.CharSet = Utf8CharsetType;
-                requestMessage.Headers.Accept.Add(acceptHeader);
+                if (requestInfo.HttpMethod == HttpCommandInfo.PostCommand)
+                {
+                    MediaTypeWithQualityHeaderValue acceptHeader = new MediaTypeWithQualityHeaderValue(JsonMimeType);
+                    acceptHeader.CharSet = Utf8CharsetType;
+                    requestMessage.Headers.Accept.Add(acceptHeader);
 
-                byte[] bytes = Encoding.UTF8.GetBytes(eventArgs.RequestBody);
-                requestMessage.Content = new ByteArrayContent(bytes, 0, bytes.Length);
+                    byte[] bytes = Encoding.UTF8.GetBytes(eventArgs.RequestBody);
+                    requestMessage.Content = new ByteArrayContent(bytes, 0, bytes.Length);
 
-                MediaTypeHeaderValue contentTypeHeader = new MediaTypeHeaderValue(JsonMimeType);
-                contentTypeHeader.CharSet = Utf8CharsetType;
-                requestMessage.Content.Headers.ContentType = contentTypeHeader;
-            }
+                    MediaTypeHeaderValue contentTypeHeader = new MediaTypeHeaderValue(JsonMimeType);
+                    contentTypeHeader.CharSet = Utf8CharsetType;
+                    requestMessage.Content.Headers.ContentType = contentTypeHeader;
+                }
+
+                using (HttpResponseMessage responseMessage = await this.client.SendAsync(requestMessage))
+                {
+                    HttpResponseInfo httpResponseInfo = new HttpResponseInfo();
+                    httpResponseInfo.Body = await responseMessage.Content.ReadAsStringAsync();
+                    httpResponseInfo.ContentType = responseMessage.Content.Headers.ContentType.ToString();
+                    httpResponseInfo.StatusCode = responseMessage.StatusCode;
 
-            HttpResponseMessage responseMessage = await this.client.SendAsync(requestMessage);
-            HttpResponseInfo httpResponseInfo = new HttpResponseInfo();
-            httpResponseInfo.Body = await responseMessage.Content.ReadAsStringAsync();
-            httpResponseInfo.ContentType = responseMessage.Content.Headers.ContentType.ToString();
-            httpResponseInfo.StatusCode = responseMessage.StatusCode;
-            return httpResponseInfo;
+                    return httpResponseInfo;
+                }
+            }
         }
 
         private Response CreateResponse(HttpResponseInfo responseInfo)