Adding macro to enable changing SSL library (Part 1)

ios/crnet/crnet_environment.mm

 // 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.
 
 #include "ios/crnet/crnet_environment.h"
 
 #import <Foundation/Foundation.h>
 
 #include <utility>
 
@@ skipping 135 matching lines @@
 
 // static
 void CrNetEnvironment::Initialize() {
   DCHECK_EQ([NSThread currentThread], [NSThread mainThread]);
   if (!g_at_exit_)
     g_at_exit_ = new base::AtExitManager;
 
   CHECK(base::i18n::InitializeICU());
   url::Initialize();
   base::CommandLine::Init(0, nullptr);
+
+#if defined(USE_NSS_VERIFIER)
   // This needs to happen on the main thread. NSPR's initialization sets up its
   // memory allocator; if this is not done before other threads are created,
   // this initialization can race to cause accidental free/allocation
   // mismatches.
   crypto::EnsureNSPRInit();
+#endif
+
   // Without doing this, StatisticsRecorder::FactoryGet() leaks one histogram
   // per call after the first for a given name.
   base::StatisticsRecorder::Initialize();
 
   // Create a message loop on the UI thread.
   base::MessageLoop* main_message_loop =
       new base::MessageLoop(base::MessageLoop::TYPE_UI);
 #pragma unused(main_message_loop)
   base::MessageLoopForUI::current()->Attach();
 }
@@ skipping 110 matching lines @@
       new base::Thread("Chrome File User Blocking Thread"));
   file_user_blocking_thread_->StartWithOptions(
       base::Thread::Options(base::MessageLoop::TYPE_IO, 0));
 
   // The network change notifier must be initialized so that registered
   // delegates will receive callbacks.
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
   proxy_config_service_ = net::ProxyService::CreateSystemProxyConfigService(
       network_io_thread_->task_runner(), nullptr);
 
+#if defined(USE_NSS_VERIFIER)
   net::SetURLRequestContextForNSSHttpIO(main_context_.get());
+#endif
   main_context_getter_ = new CrNetURLRequestContextGetter(
       main_context_.get(), network_io_thread_->task_runner());
   base::subtle::MemoryBarrier();
   PostToNetworkThread(FROM_HERE,
       base::Bind(&CrNetEnvironment::InitializeOnNetworkThread,
                  base::Unretained(this)));
 
   SetRequestFilterBlock(nil);
 }
 
 void CrNetEnvironment::InstallIntoSessionConfiguration(
     NSURLSessionConfiguration* config) {
   config.protocolClasses = @[ [CRNPauseableHTTPProtocolHandler class] ];
 }
 
 CrNetEnvironment::~CrNetEnvironment() {
   net::HTTPProtocolHandlerDelegate::SetInstance(nullptr);
+#if defined(USE_NSS_VERIFIER)
   net::SetURLRequestContextForNSSHttpIO(nullptr);
+#endif
 }
 
 net::URLRequestContextGetter* CrNetEnvironment::GetMainContextGetter() {
   return main_context_getter_.get();
 }
 
 void CrNetEnvironment::SetHTTPProtocolHandlerRegistered(bool registered) {
   if (registered) {
     // Disable the default cache.
     [NSURLCache setSharedURLCache:[EmptyNSURLCache emptyNSURLCache]];
@@ skipping 173 matching lines @@
 
   return user_agent_settings->GetUserAgent();
 }
 
 void CrNetEnvironment::ClearCache(ClearCacheCallback callback) {
   PostToNetworkThread(
       FROM_HERE,
       base::Bind(&net::ClearHttpCache, main_context_getter_,
                  network_io_thread_->task_runner(), base::BindBlock(callback)));
 }