Handle online and offline redirects via interceptor and offline scheme

chrome/browser/android/offline_pages/offline_page_request_redirect_job.cc

Index: chrome/browser/android/offline_pages/offline_page_request_redirect_job.cc
diff --git a/chrome/browser/android/offline_pages/offline_page_request_redirect_job.cc b/chrome/browser/android/offline_pages/offline_page_request_redirect_job.cc
new file mode 100644
index 0000000000000000000000000000000000000000..52b6745167410415f91d16d4d023e11b3606bc05
--- /dev/null
+++ b/chrome/browser/android/offline_pages/offline_page_request_redirect_job.cc
@@ -0,0 +1,88 @@
+// 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.
+
+#include "chrome/browser/android/offline_pages/offline_page_request_redirect_job.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "net/url_request/url_request.h"
+
+namespace offline_pages {
+
+OfflinePageRequestRedirectJob::OfflinePageRequestRedirectJob(
+    net::URLRequest* request,
+    net::NetworkDelegate* network_delegate,
+    Delegate* delegate)
+    : net::URLRequestJob(request, network_delegate),
+      delegate_(delegate),
+      is_started_(false),
+      state_(State::NOT_DETERMINED),
+      weak_ptr_factory_(this) {
+}
+
+OfflinePageRequestRedirectJob::~OfflinePageRequestRedirectJob() {
+}
+
+void OfflinePageRequestRedirectJob::Start() {
+  MaybeStartRequest();
+}
+
+void OfflinePageRequestRedirectJob::Kill() {
+  net::URLRequestJob::Kill();
+  weak_ptr_factory_.InvalidateWeakPtrs();
+}
+
+bool OfflinePageRequestRedirectJob::IsRedirectResponse(GURL* location,
+                                                       int* http_status_code) {
+  DCHECK(redirect_url_.is_valid());
+
+  *location = redirect_url_;
+  *http_status_code = 302;  // Simulate a temporary redirect.
+  return true;
+}
+
+base::WeakPtr<OfflinePageRequestRedirectJob>
+OfflinePageRequestRedirectJob::GetWeakPtr() {
+  return weak_ptr_factory_.GetWeakPtr();
+}
+
+void OfflinePageRequestRedirectJob::FallbackToDefault() {
+  state_ = State::FALLBACK_TO_DEFAULT;
+  MaybeStartRequest();
+}
+
+void OfflinePageRequestRedirectJob::SetRedirectURL(const GURL& url) {
+  redirect_url_ = url;
+  state_ = State::DO_REDIRECT;
+  MaybeStartRequest();
+}
+
+void OfflinePageRequestRedirectJob::MaybeStartRequest() {
+  if (is_started_)
+    return;
+
+  switch (state_) {
+    case State::NOT_DETERMINED:
+      // Still waiting to get offline data.
+      return;
+
+    case State::FALLBACK_TO_DEFAULT:
+      // Restart the request to create a new job. Our request handler will
+      // return nullptr, and the default job should be created.
+      is_started_ = true;
+      delegate_->OnPrepareToRestart();
+      URLRequestJob::NotifyRestartRequired();
+      return;
+
+    case State::DO_REDIRECT:
+      is_started_ = true;
+      NotifyHeadersComplete();
+      return;
+  }
+
+  NOTREACHED();
+}
+
+}  // namespace offline_pages