Conditionally set enable_ipc_fuzzer for GN builds.

tools/ipc_fuzzer/BUILD.gn

 # Copyright 2016 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("//tools/ipc_fuzzer/ipc_fuzzer.gni")
 
 config("ipc_fuzzer_config") {
   defines = [ "ENABLE_IPC_FUZZER" ]
 }
 
 config("ipc_fuzzer_tool_config") {
   defines = [
     "ENABLE_IPC_FUZZER",
     "USE_CUPS",
   ]
   include_dirs = [ "." ]
 }
 
-if (enable_ipc_fuzzer && (is_linux || is_mac || is_win)) {
+if (enable_ipc_fuzzer) {
   assert(!is_component_build, "IPC fuzzer does not support component builds.")
 
   group("ipc_fuzzer_all") {
     deps = [
       "//tools/ipc_fuzzer/fuzzer:ipc_fuzzer",
       "//tools/ipc_fuzzer/message_dump:ipc_message_dump",
       "//tools/ipc_fuzzer/message_replay:ipc_fuzzer_replay",
       "//tools/ipc_fuzzer/message_tools:ipc_message_list",
       "//tools/ipc_fuzzer/message_tools:ipc_message_util",
     ]
   }
 } else {
   group("ipc_fuzzer_all") {
   }
 }