[subresource_filter] SB throttle can send multiple speculative requests.

components/subresource_filter/content/browser/subresource_filter_safe_browsing_client.cc

+// Copyright 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/subresource_filter/content/browser/subresource_filter_safe_browsing_client.h"
+
+#include <utility>
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/single_thread_task_runner.h"
+#include "components/subresource_filter/content/browser/subresource_filter_safe_browsing_activation_throttle.h"
+#include "components/subresource_filter/content/browser/subresource_filter_safe_browsing_client_request.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace subresource_filter {
+
+SubresourceFilterSafeBrowsingClient::SubresourceFilterSafeBrowsingClient(
+    scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager> database_manager,
+    base::WeakPtr<SubresourceFilterSafeBrowsingActivationThrottle> throttle,
+    scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> throttle_task_runner)
+    : database_manager_(std::move(database_manager)),
+      throttle_(std::move(throttle)),
+      io_task_runner_(std::move(io_task_runner)),
+      throttle_task_runner_(std::move(throttle_task_runner)) {}
+
+SubresourceFilterSafeBrowsingClient::~SubresourceFilterSafeBrowsingClient() {}
+
+void SubresourceFilterSafeBrowsingClient::CheckUrlOnIO(const GURL& url,
+                                                       size_t request_id) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(!url.is_empty());
+
+  auto request = base::MakeUnique<SubresourceFilterSafeBrowsingClientRequest>(
+      url, request_id, database_manager_, io_task_runner_, this);
+  auto* raw_request = request.get();
+  DCHECK(requests_.find(raw_request) == requests_.end());
+  requests_[raw_request] = std::move(request);
+  raw_request->Start();
+  // Careful, |raw_request| can be destroyed after this line.
+}
+
+void SubresourceFilterSafeBrowsingClient::OnCheckBrowseUrlResult(
+    SubresourceFilterSafeBrowsingClientRequest* request,
+    const CheckResult& check_result) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  throttle_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&SubresourceFilterSafeBrowsingActivationThrottle::
+                                OnCheckUrlResultOnUI,
+                            throttle_, check_result));
+
+  DCHECK(requests_.find(request) != requests_.end());
+  requests_.erase(request);
+}
+
+}  // namespace subresource_filter