Add option to gen_snapshot for creating a Makefile describing a snapshot's dependencies.

runtime/vm/log.cc

 // Copyright (c) 2015, 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 "vm/log.h"
 
 #include "vm/flags.h"
+#include "vm/isolate.h"
 #include "vm/thread.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, force_log_flush, false, "Always flush log messages.");
 
 DEFINE_FLAG(charp,
             isolate_log_filter,
             NULL,
             "Log isolates whose name include the filter. "
@@ skipping 159 matching lines @@
   log_->EnableManualFlush();
 }
 
 
 LogBlock::~LogBlock() {
   log_->Flush(cursor_);
   log_->DisableManualFlush();
 }
 
 }  // namespace dart