Make checkAtmosphereSupport() non-static (#12136)

Cherry pick https://github.com/vaadin/framework/pull/12131

server/src/main/java/com/vaadin/server/VaadinService.java

@@ -134,7 +134,7 @@ public abstract class VaadinService implements Serializable {
 
     private Iterable<RequestHandler> requestHandlers;
 
-    private boolean atmosphereAvailable = checkAtmosphereSupport();
+    private Boolean atmosphereAvailable = null;
 
     /**
      * Keeps track of whether a warning about missing push support has already
@@ -1652,7 +1652,7 @@ public abstract class VaadinService implements Serializable {
      *         is not available.
      */
     public boolean ensurePushAvailable() {
-        if (atmosphereAvailable) {
+        if (isAtmosphereAvailable()) {
             return true;
         } else {
             if (!pushWarningEmitted) {
@@ -1664,7 +1664,7 @@ public abstract class VaadinService implements Serializable {
         }
     }
 
-    private static boolean checkAtmosphereSupport() {
+    private boolean checkAtmosphereSupport() {
         String rawVersion = AtmospherePushConnection.getAtmosphereVersion();
         if (rawVersion == null) {
             return false;
@@ -1687,6 +1687,9 @@ public abstract class VaadinService implements Serializable {
      * @return true if Atmosphere is available, false otherwise
      */
     protected boolean isAtmosphereAvailable() {
+        if (atmosphereAvailable == null) {
+            atmosphereAvailable = checkAtmosphereSupport();
+        }
         return atmosphereAvailable;
     }
 

uitest/src/test/java/com/vaadin/tests/VerifyBrowserVersionTest.java

@@ -25,7 +25,7 @@ public class VerifyBrowserVersionTest extends MultiBrowserTest {
             // Chrome version does not necessarily match the desired version
             // because of auto updates...
             browserIdentifier = getExpectedUserAgentString(
-                    getDesiredCapabilities()) + "86";
+                    getDesiredCapabilities()) + "87";
         } else {
             browserIdentifier = getExpectedUserAgentString(desiredCapabilities)
                     + desiredCapabilities.getVersion();