Second step towards loading the core library scripts directly from the sources

runtime/include/dart_api.h

Index: runtime/include/dart_api.h
===================================================================
--- runtime/include/dart_api.h	(revision 22375)
+++ runtime/include/dart_api.h	(working copy)
@@ -646,8 +646,39 @@
  */
 typedef void (*Dart_IsolateShutdownCallback)(void* callback_data);
 
-typedef void* (*Dart_FileOpenCallback)(const char* name);
+/**
+ * Callbacks provided by the embedder for file operations. If the
+ * embedder does not allow file operations these callbacks can be
+ * NULL.
+ *
+ * Dart_FileOpenCallback - opens a file for reading or writing.
+ * \param name The name of the file to open.
+ * \param write A boolean variable which indicates if the file is to
+ *   opened for writing. If there is an existing file it needs to truncated.
+ *
+ * Dart_FileReadCallback - Read contents of file.
+ * \param data Buffer allocated in the callback into which the contents
+ *   of the file are read into. It is the responsibility of the caller to
+ *   free this buffer.
+ * \param file_length A variable into which the length of the file is returned.
+ *   In the case of an error this value would be -1.
+ * \param stream Handle to the opened file.
+ *
+ * Dart_FileWriteCallback - Write data into file.
+ * \param data Buffer which needs to be written into the file.
+ * \param length Length of the buffer.
+ * \param stream Handle to the opened file.
+ *
+ * Dart_FileCloseCallback - Closes the opened file.
+ * \param stream Handle to the opened file.
+ *
+ */
+typedef void* (*Dart_FileOpenCallback)(const char* name, bool write);
 
+typedef void (*Dart_FileReadCallback)(const uint8_t** data,
+                                      intptr_t* file_length,
+                                      void* stream);
+
 typedef void (*Dart_FileWriteCallback)(const void* data,
                                        intptr_t length,
                                        void* stream);
@@ -675,6 +706,7 @@
     Dart_IsolateUnhandledExceptionCallback unhandled_exception,
     Dart_IsolateShutdownCallback shutdown,
     Dart_FileOpenCallback file_open,
+    Dart_FileReadCallback file_read,
     Dart_FileWriteCallback file_write,
     Dart_FileCloseCallback file_close);