Wrap the p2p transport API in a compile time flag.

chrome/browser/about_flags.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/about_flags.h"
 
 #include <algorithm>
 #include <iterator>
 #include <map>
 #include <set>
@@ skipping 219 matching lines @@
     IDS_FLAGS_WEBAUDIO_NAME,
     IDS_FLAGS_WEBAUDIO_DESCRIPTION,
     kOsMac,  // TODO(crogers): add windows and linux when FFT is ready.
     SINGLE_VALUE_TYPE(switches::kEnableWebAudio)
   },
   {
     "p2papi",
     IDS_FLAGS_P2P_API_NAME,
     IDS_FLAGS_P2P_API_DESCRIPTION,
     kOsAll,
+#if defined(ENABLE_P2P_APIS)
     SINGLE_VALUE_TYPE(switches::kEnableP2PApi)
+#else
+    SINGLE_VALUE_TYPE("")
+#endif
   },
   {
     "focus-existing-tab-on-open",  // FLAGS:RECORD_UMA
     IDS_FLAGS_FOCUS_EXISTING_TAB_ON_OPEN_NAME,
     IDS_FLAGS_FOCUS_EXISTING_TAB_ON_OPEN_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kFocusExistingTabOnOpen)
   },
   {
     "new-tab-page-4",
@@ skipping 478 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags