Don't use IsolateData for the exit hook as multiple embedders share the dart/bin while using differ…

runtime/bin/process_android.cc

Index: runtime/bin/process_android.cc
diff --git a/runtime/bin/process_android.cc b/runtime/bin/process_android.cc
index 00d6ca2df8de800d788a781a0e1b1219ce3b149d..89c5bf7d599a0bd349a1dff723edf4ddf7786529 100644
--- a/runtime/bin/process_android.cc
+++ b/runtime/bin/process_android.cc
@@ -34,6 +34,7 @@ namespace bin {
 
 int Process::global_exit_code_ = 0;
 Mutex* Process::global_exit_code_mutex_ = new Mutex();
+Process::ExitHook Process::exit_hook_ = NULL;
 
 // ProcessInfo is used to map a process id to the file descriptor for
 // the pipe used to communicate the exit code of the process to Dart.