Fix GN NaCl Debug build of base.

build/config/BUILD.gn

 # Copyright (c) 2013 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.
 
 import("//build/config/allocator.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/module_args/v8.gni")
 
@@ skipping 218 matching lines @@
 
 # Debug/release ----------------------------------------------------------------
 
 config("debug") {
   defines = [
     "_DEBUG",
     "DYNAMIC_ANNOTATIONS_ENABLED=1",
     "WTF_USE_DYNAMIC_ANNOTATIONS=1",
   ]
 
+  if (is_nacl) {
+    defines += [ "DYNAMIC_ANNOTATIONS_PREFIX=NACL_" ]
+  }
+
   if (is_win) {
     if (disable_iterator_debugging) {
       # Iterator debugging is enabled by the compiler on debug builds, and we
       # have to tell it to turn it off.
       defines += [ "_HAS_ITERATOR_DEBUGGING=0" ]
     }
   } else if (is_linux && !is_android && current_cpu == "x64" &&
              !disable_iterator_debugging) {
     # Enable libstdc++ debugging facilities to help catch problems early, see
     # http://crbug.com/65151 .
@@ skipping 72 matching lines @@
       "CoreFoundation.framework",
       "CoreGraphics.framework",
       "CoreText.framework",
       "Foundation.framework",
       "UIKit.framework",
     ]
   } else if (is_linux) {
     libs = [ "dl" ]
   }
 }