Add extension system and PDF viewer to Qt WebEngine

Adds the Chromium extensiuon system to Qt WebEngine.
Currently, it only exposes internal APIs to the internal
PDF viewer extension.

To load a PDF, simply navigate to it.

This feature can be configured via the webengine-extensions flag
and is turned on by default.

Needs patch in Chromium 71-based to build.

Adaptations to 71-based from 69-based include:
  * Flag out update installation, add crx file dependency
  * Move PostTask over to 71-based implementation
  * Move extensions API providers to 71-based implementaion
  * Don't use custom guest view and mime handler view delegates
  * Adapt the URLRequestResourceBundleJob to match new interface
  * Move extension system initialization to end of profile constructor

Change-Id: I4fa5149057291bb5847f048534c11820cd7ff58c
Fixes: QTBUG-50556
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 182 insertions, 0 deletions

diff --git a/src/core/renderer/extensions/resource_request_policy_qt.cpp b/src/core/renderer/extensions/resource_request_policy_qt.cpp
new file mode 100644
index 000000000..dc5a90120
--- /dev/null
+++ b/src/core/renderer/extensions/resource_request_policy_qt.cpp
@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// based on chrome/renderer/extensions/resource_request_policy.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 "resource_request_policy_qt.h"
+
+#include "base/strings/stringprintf.h"
+#include "chrome/common/url_constants.h"
+#include "extensions/common/constants.h"
+#include "extensions/common/manifest_handlers/web_accessible_resources_info.h"
+#include "extensions/common/manifest_handlers/webview_info.h"
+#include "extensions/renderer/dispatcher.h"
+#include "third_party/blink/public/web/web_console_message.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+
+namespace extensions {
+ResourceRequestPolicyQt::ResourceRequestPolicyQt(Dispatcher *dispatcher)
+        : m_dispatcher(dispatcher)
+{
+}
+
+void ResourceRequestPolicyQt::OnExtensionLoaded(const Extension &extension)
+{
+    if (WebAccessibleResourcesInfo::HasWebAccessibleResources(&extension)
+        || WebviewInfo::HasWebviewAccessibleResources(extension, m_dispatcher->webview_partition_id())
+//          // Hosted app icons are accessible.
+//          // TODO(devlin): Should we incorporate this into
+//          // WebAccessibleResourcesInfo?
+//        || (extension.is_hosted_app() && !IconsInfo::GetIcons(&extension).empty())
+       ) {
+        m_web_accessible_ids.insert(extension.id());
+    }
+}
+
+void ResourceRequestPolicyQt::OnExtensionUnloaded(const ExtensionId &extension_id)
+{
+    m_web_accessible_ids.erase(extension_id);
+}
+
+// Returns true if the chrome-extension:// |resource_url| can be requested
+// from |frame_url|. In some cases this decision is made based upon how
+// this request was generated. Web triggered transitions are more restrictive
+// than those triggered through UI.
+bool ResourceRequestPolicyQt::CanRequestResource(const GURL &resource_url,
+                                                 blink::WebLocalFrame *frame,
+                                                 ui::PageTransition transition_type)
+{
+    CHECK(resource_url.SchemeIs(kExtensionScheme));
+
+    GURL frame_url = frame->GetDocument().Url();
+
+    // The page_origin may be GURL("null") for unique origins like data URLs,
+    // but this is ok for the checks below.  We only care if it matches the
+    // current extension or has a devtools scheme.
+    GURL page_origin = url::Origin(frame->Top()->GetSecurityOrigin()).GetURL();
+
+    GURL extension_origin = resource_url.GetOrigin();
+
+    // We always allow loads in the following cases, regardless of web accessible
+    // resources:
+
+    // Empty urls (needed for some edge cases when we have empty urls).
+    if (frame_url.is_empty())
+        return true;
+
+    // Extensions requesting their own resources (frame_url check is for images,
+    // page_url check is for iframes).
+    // TODO(devlin): We should be checking the ancestor chain, not just the
+    // top-level frame. Additionally, we should be checking the security origin
+    // of the frame, to account for about:blank subframes being scripted by an
+    // extension parent (though we'll still need the frame origin check for
+    // sandboxed frames).
+    if (frame_url.GetOrigin() == extension_origin || page_origin == extension_origin)
+        return true;
+
+    if (!ui::PageTransitionIsWebTriggerable(transition_type))
+        return true;
+
+    // Unreachable web page error page (to allow showing the icon of the
+    // unreachable app on this page).
+    if (frame_url == content::kUnreachableWebDataURL)
+        return true;
+
+    bool is_dev_tools = page_origin.SchemeIs(content::kChromeDevToolsScheme);
+    // Note: we check |web_accessible_ids_| (rather than first looking up the
+    // extension in the registry and checking that) to be more resistant against
+    // timing attacks. This way, determining access for an extension that isn't
+    // installed takes the same amount of time as determining access for an
+    // extension with no web accessible resources. We aren't worried about any
+    // extensions with web accessible resources, since those are inherently
+    // identifiable.
+    if (!is_dev_tools && !m_web_accessible_ids.count(extension_origin.host()))
+        return false;
+
+    const Extension* extension = RendererExtensionRegistry::Get()->GetExtensionOrAppByURL(resource_url);
+    if (is_dev_tools) {
+        // Allow the load in the case of a non-existent extension. We'll just get a
+        // 404 from the browser process.
+        // TODO(devlin): Can this happen? Does devtools potentially make requests
+        // to non-existent extensions?
+        if (!extension)
+            return true;
+//        // Devtools (chrome-extension:// URLs are loaded into frames of devtools to
+//        // support the devtools extension APIs).
+//        if (!chrome_manifest_urls::GetDevToolsPage(extension).is_empty())
+//            return true;
+    }
+
+    DCHECK(extension);
+
+    // Disallow loading of packaged resources for hosted apps. We don't allow
+    // hybrid hosted/packaged apps. The one exception is access to icons, since
+    // some extensions want to be able to do things like create their own
+    // launchers.
+    base::StringPiece resource_root_relative_path =
+            resource_url.path_piece().empty() ? base::StringPiece()
+                                              : resource_url.path_piece().substr(1);
+    if (extension->is_hosted_app() /*&& !IconsInfo::GetIcons(extension).ContainsPath(resource_root_relative_path)*/) {
+        LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
+                   << "hosted app.";
+        return false;
+    }
+
+    // Disallow loading of extension resources which are not explicitly listed
+    // as web or WebView accessible if the manifest version is 2 or greater.
+    if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(extension, resource_url.path()) &&
+        !WebviewInfo::IsResourceWebviewAccessible(extension, m_dispatcher->webview_partition_id(), resource_url.path()))
+    {
+        std::string message = base::StringPrintf(
+                    "Denying load of %s. Resources must be listed in the "
+                    "web_accessible_resources manifest key in order to be loaded by "
+                    "pages outside the extension.",
+                    resource_url.spec().c_str());
+        frame->AddMessageToConsole(blink::WebConsoleMessage(blink::WebConsoleMessage::kLevelError, blink::WebString::FromUTF8(message)));
+        return false;
+    }
+
+    return true;
+}
+
+} // namespace extensions