Check result of ApiBlacklist query in client.

chrome/browser/permissions/permission_blacklist_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 "chrome/browser/permissions/permission_blacklist_client.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 23 matching lines @@
     const GURL& request_origin,
     content::WebContents* web_contents,
     int timeout,
     base::Callback<void(bool)> callback)
     : content::WebContentsObserver(web_contents),
       db_manager_(db_manager),
       permission_type_(permission_type),
       callback_(callback),
       timeout_(timeout),
       is_active_(true) {
-  // Balanced by a call to Release() in OnCheckApiBlacklistUrlResult().
+  // Balanced by a call to Release() in EvaluateBlacklistResultOnUiThread().
   AddRef();
   content::BrowserThread::PostTask(
       content::BrowserThread::IO, FROM_HERE,
       base::Bind(&PermissionBlacklistClient::StartCheck, this, request_origin));
 }
 
 PermissionBlacklistClient::~PermissionBlacklistClient() {}
 
 void PermissionBlacklistClient::StartCheck(const GURL& request_origin) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
   // Start the timer to interrupt into the client callback method with an
   // empty response if Safe Browsing times out.
   safe_browsing::ThreatMetadata empty_metadata;
   timer_ = base::MakeUnique<base::OneShotTimer>();
   timer_->Start(
       FROM_HERE, base::TimeDelta::FromMilliseconds(timeout_),
       base::Bind(&PermissionBlacklistClient::OnCheckApiBlacklistUrlResult, this,
                  request_origin, empty_metadata));
-  db_manager_->CheckApiBlacklistUrl(request_origin, this);
+  // If CheckApiBlacklistUrl returns true, no asynchronous call to |this| will
+  // be made, so just directly call through to OnCheckApiBlacklistUrlResult.
+  if (db_manager_->CheckApiBlacklistUrl(request_origin, this))
+    OnCheckApiBlacklistUrlResult(request_origin, empty_metadata);
 }
 
 void PermissionBlacklistClient::OnCheckApiBlacklistUrlResult(
     const GURL& url,
     const safe_browsing::ThreatMetadata& metadata) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-
   if (timer_->IsRunning())
     timer_->Stop();
   else
     db_manager_->CancelApiCheck(this);
   timer_.reset(nullptr);
 
   bool permission_blocked =
       metadata.api_permissions.find(
           PermissionUtil::ConvertPermissionTypeToSafeBrowsingName(
               permission_type_)) != metadata.api_permissions.end();
@@ skipping 10 matching lines @@
 
   if (is_active_)
     callback_.Run(permission_blocked);
   Release();
 }
 
 void PermissionBlacklistClient::WebContentsDestroyed() {
   is_active_ = false;
   Observe(nullptr);
 }