Added slim versions of output streams.

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
 v8_compress_startup_data = "off"
 v8_deprecation_warnings = false
 v8_enable_disassembler = false
 v8_enable_gdbjit = false
@@ skipping 656 matching lines @@
     "src/messages.h",
     "src/msan.h",
     "src/natives.h",
     "src/objects-debug.cc",
     "src/objects-inl.h",
     "src/objects-printer.cc",
     "src/objects-visiting.cc",
     "src/objects-visiting.h",
     "src/objects.cc",
     "src/objects.h",
+    "src/optimizing-compiler-thread.cc",
     "src/optimizing-compiler-thread.h",
-    "src/optimizing-compiler-thread.cc",
+    "src/ostreams.cc",
+    "src/ostreams.h",
     "src/parser.cc",
     "src/parser.h",
     "src/platform/elapsed-timer.h",
     "src/platform/time.cc",
     "src/platform/time.h",
     "src/platform.h",
     "src/platform/condition-variable.cc",
     "src/platform/condition-variable.h",
     "src/platform/mutex.cc",
     "src/platform/mutex.h",
@@ skipping 464 matching lines @@
     deps = [
       ":v8_base",
       ":v8_nosnapshot",
     ]
   }
 
   direct_dependent_configs = [ ":external_config" ]
 }
 
 }