Don't use global variables for capturing stdio.

runtime/bin/main.cc

 // 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.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_tools_api.h"
@@ skipping 1037 matching lines @@
   Dart_Handle args[] = {paths, keys, values};
   Dart_Handle result = Dart_Invoke(io_lib, handler_function_name, 3, args);
   if (Dart_IsError(result)) return ServiceRequestError(result);
   const char *json;
   result = Dart_StringToCString(result, &json);
   if (Dart_IsError(result)) return ServiceRequestError(result);
   return strdup(json);
 }
 
 
-extern bool capture_stdio;
-extern bool capture_stdout;
-extern bool capture_stderr;
 static const char* kStdoutStreamId = "Stdout";
 static const char* kStderrStreamId = "Stderr";
 
 
 static bool ServiceStreamListenCallback(const char* stream_id) {
   if (strcmp(stream_id, kStdoutStreamId) == 0) {
-    capture_stdio = true;
-    capture_stdout = true;
+    File::set_capture_stdout(true);
     return true;
   } else if (strcmp(stream_id, kStderrStreamId) == 0) {
-    capture_stdio = true;
-    capture_stderr = true;
+    File::set_capture_stderr(true);
     return true;
   }
   return false;
 }
 
 
 static void ServiceStreamCancelCallback(const char* stream_id) {
   if (strcmp(stream_id, kStdoutStreamId) == 0) {
-    capture_stdout = false;
+    File::set_capture_stdout(false);
   } else if (strcmp(stream_id, kStderrStreamId) == 0) {
-    capture_stderr = false;
+    File::set_capture_stderr(false);
   }
-  capture_stdio = (capture_stdout || capture_stderr);
 }
 
 
 static void WriteSnapshotFile(const char* filename,
                               const uint8_t* buffer,
                               const intptr_t size) {
   File* file = File::Open(filename, File::kWriteTruncate);
   ASSERT(file != NULL);
   if (!file->WriteFully(buffer, size)) {
     ErrorExit(kErrorExitCode,
@@ skipping 426 matching lines @@
   Platform::Exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }