Implement rewind: drop one or more frames from the debugger.

runtime/vm/json_stream.cc

 // Copyright (c) 2013, 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.
 
 #include "platform/assert.h"
 
 #include "include/dart_native_api.h"
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/json_stream.h"
@@ skipping 121 matching lines @@
     case kInternalError:
       return "Internal error";
     case kFeatureDisabled:
       return "Feature is disabled";
     case kCannotAddBreakpoint:
       return "Cannot add breakpoint";
     case kIsolateMustBeRunnable:
       return "Isolate must be runnable";
     case kIsolateMustBePaused:
       return "Isolate must be paused";
+    case kCannotResume:
+      return "Cannot resume execution";
     case kIsolateIsReloading:
       return "Isolate is reloading";
     case kFileSystemAlreadyExists:
       return "File system already exists";
     case kFileSystemDoesNotExist:
       return "File system does not exist";
     case kFileDoesNotExist:
       return "File does not exist";
     case kIsolateReloadFailed:
       return "Isolate reload failed";
@@ skipping 831 matching lines @@
   ASSERT(len == len2);
   stream_->buffer_.AddChar('"');
   stream_->AddEscapedUTF8String(p);
   stream_->buffer_.AddChar('"');
   free(p);
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart