- Implement a first cut for const String.env in the VM to allow

runtime/include/dart_api.h

Index: runtime/include/dart_api.h
===================================================================
--- runtime/include/dart_api.h	(revision 27984)
+++ runtime/include/dart_api.h	(working copy)
@@ -1466,7 +1466,7 @@
 /**
  * Gets the data corresponding to the string object. This function returns
  * the data only for Latin-1 (ISO-8859-1) string objects. For all other
- * string objects it return and error.
+ * string objects it returns an error.
  *
  * \param str A string.
  * \param latin1_array An array allocated by the caller, used to return
@@ -2071,7 +2071,29 @@
 /* TODO(turnidge): Consider renaming to NativeFunctionResolver or
  * NativeResolver. */
 
+/*
+ * ==============
+ * Configurations
+ * ==============
+ */
+
+typedef enum {
+  kStringConfig = 0,
+  kIntegerConfig,
+  kBoolConfig
+} Dart_ConfigType;
+
+/* TODO(iposva): Document. */
+typedef Dart_Handle (*Dart_ConfigCallback)(Dart_ConfigType type,
+                                           Dart_Handle name);
+
 /**
+ * Sets the configuration callback for the current isolate. This callback is
+ * used to lookup configuration values by name in the current environment.
+ */
+DART_EXPORT Dart_Handle Dart_SetConfigCallback(Dart_ConfigCallback callback);
+
+/**
  * Sets the callback used to resolve native functions for a library.
  *
  * \param library A library.