Use the previews black list for offline previews

chrome/browser/profiles/profile_impl_io_data.cc

 // Copyright (c) 2012 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/profiles/profile_impl_io_data.h"
 
 #include <memory>
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 531 matching lines @@
       new net::FtpNetworkLayer(io_thread_globals->host_resolver.get()));
 #endif  // !defined(DISABLE_FTP_SUPPORT)
 
   std::unique_ptr<net::URLRequestJobFactoryImpl> main_job_factory(
       new net::URLRequestJobFactoryImpl());
   InstallProtocolHandlers(main_job_factory.get(), protocol_handlers);
 
   // Install the Offline Page Interceptor.
 #if defined(OS_ANDROID)
   request_interceptors.push_back(std::unique_ptr<net::URLRequestInterceptor>(
-      new offline_pages::OfflinePageRequestInterceptor()));
+      new offline_pages::OfflinePageRequestInterceptor(
+          previews_io_data()->PreviewsDeciderWeakPtr())));

[tbansal1, 2016/10/06 14:51:04]

Is there a guarantee that previews decider will outlive the
OfflinePageRequestInterceptor? I am asking because generally it is considered an
anti-pattern to expose weak ptrs publically.

[mmenke, 2016/10/06 15:02:46]

+1 to not exposing a WeakPtr this way.  Can we pass ownership instead (And while
we're at it, we could even remove PreviewsIOData from ProfileIOData, and instead
make it part of LazyParams, I think?  We'd have to create it a little later, if
that's not a problem.  If it is, we could at least move it to ProfileImplIOData
from ProfileIOData)

[RyanSturm, 2016/10/06 15:52:16]

The PreviewsIOData is used in more places than just offline pages (or it will
be), so I'll move it to ProfileImplIOData, as I don't think it will be needed on
ProfileIOData. I'll pass it as a raw pointer and add a comment about the
embedder guaranteeing it outlives the interceptor.

 #endif
 
   // The data reduction proxy interceptor should be as close to the network
   // as possible.
   request_interceptors.insert(
       request_interceptors.begin(),
       data_reduction_proxy_io_data()->CreateInterceptor().release());
   main_job_factory_ = SetUpJobFactoryDefaults(
       std::move(main_job_factory), std::move(request_interceptors),
       std::move(profile_params->protocol_handler_interceptor),
@@ skipping 244 matching lines @@
     const base::Closure& completion) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(initialized());
 
   DCHECK(transport_security_state());
   // Completes synchronously.
   transport_security_state()->DeleteAllDynamicDataSince(time);
   DCHECK(http_server_properties_manager_);
   http_server_properties_manager_->Clear(completion);
 }