[ABANDONED] [WIP] Refactor SafeBrowsingResourceThrottle in preparation for WebSocket

components/safe_browsing/resource_throttle.cc

Index: components/safe_browsing/resource_throttle.cc
diff --git a/components/safe_browsing/resource_throttle.cc b/components/safe_browsing/resource_throttle.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3cb0ef55b36472fbe90c5574f710bc5e5bcf1d1f
--- /dev/null
+++ b/components/safe_browsing/resource_throttle.cc
@@ -0,0 +1,109 @@
+// Copyright (c) 2017 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 "components/safe_browsing/resource_throttle.h"
+
+#include <utility>
+
+#include "components/safe_browsing/base_ui_manager.h"
+#include "components/security_interstitials/content/unsafe_resource.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/resource_request_info.h"
+#include "content/public/browser/web_contents.h"
+#include "net/base/load_flags.h"
+#include "net/log/net_log_capture_mode.h"
+#include "net/log/net_log_source.h"
+#include "net/log/net_log_source_type.h"
+#include "net/url_request/redirect_info.h"
+#include "net/url_request/url_request.h"
+
+namespace safe_browsing {
+
+ResourceThrottle::ResourceThrottle(
+    const net::URLRequest* request,
+    content::ResourceType resource_type,
+    scoped_refptr<SafeBrowsingDatabaseManager> database_manager,
+    scoped_refptr<BaseUIManager> ui_manager,
+    std::unique_ptr<ResourceThrottle::Delegate> delegate)
+    : request_checker_(request,
+                       resource_type,
+                       std::move(database_manager),
+                       std::move(ui_manager),
+                       this),
+      delegate_(std::move(delegate)),
+      weak_factory_(this) {}
+
+ResourceThrottle::~ResourceThrottle() {}
+
+void ResourceThrottle::WillStartRequest(bool* defer) {
+  if (request_checker_.CheckNewRequest() == RequestChecker::DEFER)
+    *defer = true;
+}
+
+void ResourceThrottle::WillProcessResponse(bool* defer) {
+  if (request_checker_.ShouldDeferResponse() == RequestChecker::DEFER)
+    *defer = true;
+}
+
+bool ResourceThrottle::MustProcessResponseBeforeReadingBody() {
+  // On Android, SafeBrowsing may only decide to cancel the request when the
+  // response has been received. Therefore, no part of it should be cached
+  // until this ResourceThrottle has been able to check the response. This
+  // prevents the following scenario:
+  //   1) A request is made for foo.com which has been hacked.
+  //   2) The request is only canceled at WillProcessResponse stage, but part of
+  //   it has been cached.
+  //   3) foo.com is no longer hacked and removed from the SafeBrowsing list.
+  //   4) The user requests foo.com, which is not on the SafeBrowsing list. This
+  //   is deemed safe. However, the resource is actually served from cache,
+  //   using the version that was previously stored.
+  //   5) This results in the  user accessing an unsafe resource without being
+  //   notified that it's dangerous.
+  // TODO(clamy): Add a browser test that checks this specific scenario.
+  return true;  // Harmless when OS != Android
+}
+
+void ResourceThrottle::WillRedirectRequest(
+    const net::RedirectInfo& redirect_info,
+    bool* defer) {
+  if (request_checker_.CheckRedirect(redirect_info.new_url) ==
+      RequestChecker::DEFER) {
+    *defer = true;
+  }
+}
+
+const char* ResourceThrottle::GetNameForLogging() const {
+  return "safe_browsing::ResourceThrottle";
+}
+
+void ResourceThrottle::MaybeDestroyPrerenderContents(
+    const net::URLRequest* request) {
+  delegate_->MaybeDestroyPrerenderContents(request);
+}
+
+RequestChecker::Delegate::WebContentsGetter
+ResourceThrottle::GetWebContentsGetterForRequest(
+    const net::URLRequest* request) const {
+  const auto* info = content::ResourceRequestInfo::ForRequest(request);
+  DCHECK(info);
+  return info->GetWebContentsGetterForRequest();
+}
+
+void ResourceThrottle::StartDisplayingBlockingPage(
+    const security_interstitials::UnsafeResource& resource,
+    scoped_refptr<BaseUIManager> ui_manager) {
+  delegate_->StartDisplayingBlockingPage(
+      resource, std::move(ui_manager),
+      base::BindOnce(&ResourceThrottle::Cancel, weak_factory_.GetWeakPtr()));
+}
+
+void ResourceThrottle::CancelResourceLoad() {
+  Cancel();
+}
+
+void ResourceThrottle::ResumeResourceRequest() {
+  Resume();
+}
+
+}  // namespace safe_browsing