Implement the zygote debug options (late-enabling -Xcheck:jni and so on).

Change-Id: I03772e7fb95fce1a19dac13f6c5f870164a4d874
diff --git a/src/debugger.cc b/src/debugger.cc
index c8f3cec..1580c76 100644
--- a/src/debugger.cc
+++ b/src/debugger.cc
@@ -20,6 +20,9 @@
 
 namespace art {
 
+// JDWP is allowed unless the Zygote forbids it.
+static bool gJdwpAllowed = true;
+
 // Was there a -Xrunjdwp or -agent argument on the command-line?
 static bool gJdwpConfigured = false;
 
@@ -150,6 +153,10 @@
   UNIMPLEMENTED(FATAL);
 }
 
+void Dbg::SetJdwpAllowed(bool allowed) {
+  gJdwpAllowed = allowed;
+}
+
 DebugInvokeReq* Dbg::GetInvokeReq() {
   UNIMPLEMENTED(FATAL);
   return NULL;