Add an API function to get a debugger stack trace from an error handle.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 5998 matching lines @@
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawStacktrace));
   }
   static RawStacktrace* New(const Array& code_array,
                             const Array& pc_offset_array,
                             Heap::Space space = Heap::kNew);
 
   RawString* FullStacktrace() const;
   const char* ToCStringInternal(intptr_t* frame_index) const;
 
+  intptr_t VisibleLength() const;
+  bool VisibleFrameInfoAt(intptr_t frame_index,
+                          String* internal_function_name,
+                          String* internal_script_url,
+                          intptr_t* internal_line_number,
+                          intptr_t* internal_col_num) const;
+
  private:
   void set_code_array(const Array& code_array) const;
   void set_pc_offset_array(const Array& pc_offset_array) const;
   void set_catch_code_array(const Array& code_array) const;
   void set_catch_pc_offset_array(const Array& pc_offset_array) const;
   bool expand_inlined() const;
 
   FINAL_HEAP_OBJECT_IMPLEMENTATION(Stacktrace, Instance);
   friend class Class;
 };
@@ skipping 266 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_