Wrap the p2p transport API in a compile time flag.

content/browser/renderer_host/browser_render_process_host.cc

Index: content/browser/renderer_host/browser_render_process_host.cc
diff --git a/content/browser/renderer_host/browser_render_process_host.cc b/content/browser/renderer_host/browser_render_process_host.cc
index b10ce640c1f4166556089ce8bf2ce8253db155db..941b94570a0d69d66bb9e4e692b9fa152b93d885 100644
--- a/content/browser/renderer_host/browser_render_process_host.cc
+++ b/content/browser/renderer_host/browser_render_process_host.cc
@@ -501,8 +501,10 @@ void BrowserRenderProcessHost::CreateMessageFilters() {
           NewCallbackWithReturnValue(
               widget_helper_.get(), &RenderWidgetHelper::GetNextRoutingID)));
 
+#if defined(ENABLE_P2P_APIS)
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableP2PApi))
     channel_->AddFilter(new P2PSocketDispatcherHost());
+#endif
 
   channel_->AddFilter(new TraceMessageFilter());
   channel_->AddFilter(new ResolveProxyMsgHelper(NULL));
@@ -712,7 +714,9 @@ void BrowserRenderProcessHost::PropagateBrowserCommandLineToRenderer(
     switches::kEnableLogging,
     switches::kEnableNaCl,
     switches::kEnableOpenMax,
+#if defined(ENABLE_P2P_APIS)
     switches::kEnableP2PApi,
+#endif
     switches::kEnablePepperTesting,
     switches::kEnablePrintPreview,
     switches::kEnableRemoting,