Cache serializingRetries value so that it doesn't have to look up the…

… flag every time.

core/src/main/java/io/grpc/internal/PickFirstLeafLoadBalancer.java

@@ -75,6 +75,7 @@ final class PickFirstLeafLoadBalancer extends LoadBalancer {
   private BackoffPolicy reconnectPolicy;
   @Nullable
   private ScheduledHandle reconnectTask = null;
+  private boolean serializingRetries = isSerializingRetries();
 
   PickFirstLeafLoadBalancer(Helper helper) {
     this.helper = checkNotNull(helper, "helper");
@@ -332,7 +333,7 @@ void processSubchannelState(SubchannelData subchannelData, ConnectivityStateInfo
    * Only called after all addresses attempted and failed (TRANSIENT_FAILURE).
    */
   private void scheduleBackoff() {
-    if (!isSerializingRetries()) {
+    if (!serializingRetries) {
       return;
     }
 
@@ -464,7 +465,7 @@ public void requestConnection() {
           break; // let the already scheduled task do its job
         }
         addressIndex.increment();
-        if (!isSerializingRetries()) {
+        if (!serializingRetries) {
           requestConnection();
         } else {
           if (!addressIndex.isValid()) {
@@ -540,7 +541,7 @@ private SubchannelData createNewSubchannel(SocketAddress addr, Attributes attrs)
   }
 
   private boolean isPassComplete() {
-    if ((!isSerializingRetries() && addressIndex.isValid())
+    if ((!serializingRetries && addressIndex.isValid())
         || subchannels.size() < addressIndex.size()) {
       return false;
     }