Only return eventhandler tokens in stacks of 8, to avoid runtime calls.

runtime/bin/eventhandler_android.h

Index: runtime/bin/eventhandler_android.h
diff --git a/runtime/bin/eventhandler_android.h b/runtime/bin/eventhandler_android.h
index 6b1bec6cad6a9c2899892529343457370f3ac702..2eee0af7997f89e108c956cde09c0bcc8547eb9a 100644
--- a/runtime/bin/eventhandler_android.h
+++ b/runtime/bin/eventhandler_android.h
@@ -33,7 +33,7 @@ class InterruptMessage {
 class SocketData {
  public:
   explicit SocketData(intptr_t fd)
-      : fd_(fd), port_(0), mask_(0), tokens_(8) {
+      : fd_(fd), port_(0), mask_(0), tokens_(16) {
     ASSERT(fd_ != -1);
   }
 
@@ -55,6 +55,8 @@ class SocketData {
   intptr_t fd() { return fd_; }
   Dart_Port port() { return port_; }
 
+  bool IsListeningSocket() { return (mask_ & (1 << kListeningSocket)) != 0; }
+
   // Returns true if the last token was taken.
   bool TakeToken() {
     ASSERT(tokens_ > 0);