Add testsupport QML API and error page signals

The testsupport API is used for test those features that are not
planned to be accessible via the public API. For example,
signals of the chromium's error page should not be visible for the
develepor but it is important to test whether the error page is loaded
properly.

Change-Id: Ie5b3265a207d05649cabd624a001a6ffe2e45971
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>

17 files changed, 441 insertions, 25 deletions

diff --git a/src/core/web_contents_adapter_client.h b/src/core/web_contents_adapter_client.h
index 2efacb460..d67accec2 100644
--- a/src/core/web_contents_adapter_client.h
+++ b/src/core/web_contents_adapter_client.h
@@ -152,10 +152,10 @@ public:
     virtual void selectionChanged() = 0;
     virtual QRectF viewportRect() const = 0;
     virtual qreal dpiScale() const = 0;
-    virtual void loadStarted(const QUrl &provisionalUrl) = 0;
+    virtual void loadStarted(const QUrl &provisionalUrl, bool isErrorPage = false) = 0;
     virtual void loadCommitted() = 0;
     virtual void loadVisuallyCommitted() = 0;
-    virtual void loadFinished(bool success, const QUrl &url, int errorCode = 0, const QString &errorDescription = QString()) = 0;
+    virtual void loadFinished(bool success, const QUrl &url, bool isErrorPage = false, int errorCode = 0, const QString &errorDescription = QString()) = 0;
     virtual void focusContainer() = 0;
     virtual void unhandledKeyEvent(QKeyEvent *event) = 0;
     virtual void adoptNewWindow(WebContentsAdapter *newWebContents, WindowOpenDisposition disposition, bool userGesture, const QRect & initialGeometry) = 0;
diff --git a/src/core/web_contents_delegate_qt.cpp b/src/core/web_contents_delegate_qt.cpp
index dd56bf2af..f69b68af5 100644
--- a/src/core/web_contents_delegate_qt.cpp
+++ b/src/core/web_contents_delegate_qt.cpp
@@ -144,6 +144,11 @@ void WebContentsDelegateQt::DidStartProvisionalLoadForFrame(content::RenderFrame
 {
     if (is_error_page) {
         m_loadingErrorFrameList.append(render_frame_host->GetRoutingID());
+
+        // Trigger LoadStarted signal for main frame's error page only.
+        if (!render_frame_host->GetParent())
+            m_viewClient->loadStarted(toQt(validated_url), true);
+
         return;
     }
 
@@ -173,7 +178,7 @@ void WebContentsDelegateQt::DidFailLoad(content::RenderFrameHost* render_frame_h
     if (m_loadingErrorFrameList.removeOne(render_frame_host->GetRoutingID()) || render_frame_host->GetParent())
         return;
 
-    m_viewClient->loadFinished(false, toQt(validated_url), error_code, toQt(error_description));
+    m_viewClient->loadFinished(false /* success */ , toQt(validated_url), false /* isErrorPage */, error_code, toQt(error_description));
     m_viewClient->loadProgressChanged(0);
 }
 
@@ -182,6 +187,11 @@ void WebContentsDelegateQt::DidFinishLoad(content::RenderFrameHost* render_frame
     if (m_loadingErrorFrameList.removeOne(render_frame_host->GetRoutingID())) {
         Q_ASSERT(validated_url.is_valid() && validated_url.spec() == content::kUnreachableWebDataURL);
         m_viewClient->iconChanged(QUrl());
+
+        // Trigger LoadFinished signal for main frame's error page only.
+        if (!render_frame_host->GetParent())
+            m_viewClient->loadFinished(true /* success */, toQt(validated_url), true /* isErrorPage */);
+
         return;
     }
 
diff --git a/src/src.pro b/src/src.pro
index ed402c582..2effb70ed 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -10,13 +10,20 @@ webengine_experimental_plugin.subdir = webengine/plugin/experimental
 webengine_experimental_plugin.target = sub-webengine-experimental-plugin
 webengine_experimental_plugin.depends = webengine
 
-
 SUBDIRS += core \
            process \
            webengine \
            webengine_plugin \
            webengine_experimental_plugin
 
+
+isQMLTestSupportApiEnabled() {
+    webengine_testsupport_plugin.subdir = webengine/plugin/testsupport
+    webengine_testsupport_plugin.target = sub-webengine-testsupport-plugin
+    webengine_testsupport_plugin.depends = webengine
+    SUBDIRS += webengine_testsupport_plugin
+}
+
 # FIXME: We probably want a bit more control over config options to tweak what to build/ship or not.
 # Another example of where this could be necessary is to make it easy to build proprietery codecs support.
 !contains(WEBENGINE_CONFIG, no_ui_delegates): SUBDIRS += webengine/ui
diff --git a/src/webengine/api/qquickwebenginetestsupport.cpp b/src/webengine/api/qquickwebenginetestsupport.cpp
new file mode 100644
index 000000000..d85e56e59
--- /dev/null
+++ b/src/webengine/api/qquickwebenginetestsupport.cpp
@@ -0,0 +1,75 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickwebenginetestsupport_p.h"
+
+#include "qquickwebengineloadrequest_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QQuickWebEngineErrorPage::QQuickWebEngineErrorPage()
+{
+}
+
+void QQuickWebEngineErrorPage::loadFinished(bool success, const QUrl &url)
+{
+    // Loading of the error page should not fail.
+    Q_ASSERT(success);
+
+    QQuickWebEngineLoadRequest loadRequest(url, QQuickWebEngineView::LoadSucceededStatus);
+    Q_EMIT loadingChanged(&loadRequest);
+    return;
+}
+
+void QQuickWebEngineErrorPage::loadStarted(const QUrl &provisionalUrl)
+{
+    QQuickWebEngineLoadRequest loadRequest(provisionalUrl, QQuickWebEngineView::LoadStartedStatus);
+    Q_EMIT loadingChanged(&loadRequest);
+}
+
+QQuickWebEngineTestSupport::QQuickWebEngineTestSupport()
+    : m_errorPage(new QQuickWebEngineErrorPage())
+{
+}
+
+QQuickWebEngineErrorPage *QQuickWebEngineTestSupport::errorPage() const
+{
+    return m_errorPage.data();
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qquickwebenginetestsupport_p.cpp"
diff --git a/src/webengine/api/qquickwebenginetestsupport_p.h b/src/webengine/api/qquickwebenginetestsupport_p.h
new file mode 100644
index 000000000..832ac2803
--- /dev/null
+++ b/src/webengine/api/qquickwebenginetestsupport_p.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKWEBENGINETESTSUPPORT_P_H
+#define QQUICKWEBENGINETESTSUPPORT_P_H
+
+#include <private/qtwebengineglobal_p.h>
+
+#include <QObject>
+#include <QUrl>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickWebEngineLoadRequest;
+
+class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineErrorPage : public QObject {
+    Q_OBJECT
+
+public:
+    QQuickWebEngineErrorPage();
+
+    void loadFinished(bool success, const QUrl &url);
+    void loadStarted(const QUrl &provisionalUrl);
+
+Q_SIGNALS:
+    void loadingChanged(QQuickWebEngineLoadRequest *loadRequest);
+};
+
+class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineTestSupport : public QObject {
+    Q_OBJECT
+    Q_PROPERTY(QQuickWebEngineErrorPage *errorPage READ errorPage)
+
+public:
+    QQuickWebEngineTestSupport();
+    QQuickWebEngineErrorPage *errorPage() const;
+
+private:
+    QScopedPointer<QQuickWebEngineErrorPage> m_errorPage;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQUICKWEBENGINETESTSUPPORT_P_H
diff --git a/src/webengine/api/qquickwebengineview.cpp b/src/webengine/api/qquickwebengineview.cpp
index 6fa3798c2..2fbf0ecb2 100644
--- a/src/webengine/api/qquickwebengineview.cpp
+++ b/src/webengine/api/qquickwebengineview.cpp
@@ -49,6 +49,11 @@
 #include "qquickwebengineprofile_p_p.h"
 #include "qquickwebenginesettings_p.h"
 #include "qquickwebenginescript_p_p.h"
+
+#ifdef ENABLE_QML_TESTSUPPORT_API
+#include "qquickwebenginetestsupport_p.h"
+#endif
+
 #include "render_widget_host_view_qt_delegate_quick.h"
 #include "render_widget_host_view_qt_delegate_quickwindow.h"
 #include "ui_delegates_manager.h"
@@ -90,6 +95,9 @@ QQuickWebEngineViewPrivate::QQuickWebEngineViewPrivate()
     , m_history(new QQuickWebEngineHistory(this))
     , m_profile(QQuickWebEngineProfile::defaultProfile())
     , m_settings(new QQuickWebEngineSettings(m_profile->settings()))
+#ifdef ENABLE_QML_TESTSUPPORT_API
+    , m_testSupport(0)
+#endif
     , contextMenuExtraItems(0)
     , loadProgress(0)
     , m_isFullScreen(false)
@@ -301,9 +309,17 @@ qreal QQuickWebEngineViewPrivate::dpiScale() const
     return m_dpiScale;
 }
 
-void QQuickWebEngineViewPrivate::loadStarted(const QUrl &provisionalUrl)
+void QQuickWebEngineViewPrivate::loadStarted(const QUrl &provisionalUrl, bool isErrorPage)
 {
     Q_Q(QQuickWebEngineView);
+    if (isErrorPage) {
+#ifdef ENABLE_QML_TESTSUPPORT_API
+        if (m_testSupport)
+            m_testSupport->errorPage()->loadStarted(provisionalUrl);
+#endif
+        return;
+    }
+
     isLoading = true;
     m_history->reset();
     m_certificateErrorControllers.clear();
@@ -325,9 +341,18 @@ Q_STATIC_ASSERT(static_cast<int>(WebEngineError::NoErrorDomain) == static_cast<i
 Q_STATIC_ASSERT(static_cast<int>(WebEngineError::CertificateErrorDomain) == static_cast<int>(QQuickWebEngineView::CertificateErrorDomain));
 Q_STATIC_ASSERT(static_cast<int>(WebEngineError::DnsErrorDomain) == static_cast<int>(QQuickWebEngineView::DnsErrorDomain));
 
-void QQuickWebEngineViewPrivate::loadFinished(bool success, const QUrl &url, int errorCode, const QString &errorDescription)
+void QQuickWebEngineViewPrivate::loadFinished(bool success, const QUrl &url, bool isErrorPage, int errorCode, const QString &errorDescription)
 {
     Q_Q(QQuickWebEngineView);
+
+    if (isErrorPage) {
+#ifdef ENABLE_QML_TESTSUPPORT_API
+        if (m_testSupport)
+            m_testSupport->errorPage()->loadFinished(success, url);
+#endif
+        return;
+    }
+
     isLoading = false;
     m_history->reset();
     if (errorCode == WebEngineError::UserAbortedError) {
@@ -703,6 +728,20 @@ void QQuickWebEngineViewPrivate::setProfile(QQuickWebEngineProfile *profile)
     }
 }
 
+#ifdef ENABLE_QML_TESTSUPPORT_API
+QQuickWebEngineTestSupport *QQuickWebEngineView::testSupport() const
+{
+    Q_D(const QQuickWebEngineView);
+    return d->m_testSupport;
+}
+
+void QQuickWebEngineView::setTestSupport(QQuickWebEngineTestSupport *testSupport)
+{
+    Q_D(QQuickWebEngineView);
+    d->m_testSupport = testSupport;
+}
+#endif
+
 void QQuickWebEngineViewPrivate::didRunJavaScript(quint64 requestId, const QVariant &result)
 {
     Q_Q(QQuickWebEngineView);
diff --git a/src/webengine/api/qquickwebengineview_p.h b/src/webengine/api/qquickwebengineview_p.h
index 3ff6ab66b..d4a492efb 100644
--- a/src/webengine/api/qquickwebengineview_p.h
+++ b/src/webengine/api/qquickwebengineview_p.h
@@ -54,6 +54,11 @@ class QQuickWebEngineSettings;
 class QQuickWebEngineViewExperimental;
 class QQuickWebEngineViewPrivate;
 
+#ifdef ENABLE_QML_TESTSUPPORT_API
+class QQuickWebEngineTestSupport;
+#endif
+
+
 class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineView : public QQuickItem {
     Q_OBJECT
     Q_PROPERTY(QUrl url READ url WRITE setUrl NOTIFY urlChanged)
@@ -69,6 +74,11 @@ class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineView : public QQuickItem {
     Q_PROPERTY(QQuickWebEngineHistory *navigationHistory READ navigationHistory CONSTANT FINAL REVISION 1)
     Q_PROPERTY(QQmlWebChannel *webChannel READ webChannel WRITE setWebChannel NOTIFY webChannelChanged REVISION 1)
     Q_PROPERTY(QQmlListProperty<QQuickWebEngineScript> userScripts READ userScripts FINAL)
+
+#ifdef ENABLE_QML_TESTSUPPORT_API
+    Q_PROPERTY(QQuickWebEngineTestSupport *testSupport READ testSupport WRITE setTestSupport FINAL)
+#endif
+
     Q_ENUMS(NavigationRequestAction);
     Q_ENUMS(NavigationType);
     Q_ENUMS(LoadStatus);
@@ -161,6 +171,11 @@ public:
     void setWebChannel(QQmlWebChannel *);
     QQuickWebEngineHistory *navigationHistory() const;
 
+#ifdef ENABLE_QML_TESTSUPPORT_API
+    QQuickWebEngineTestSupport *testSupport() const;
+    void setTestSupport(QQuickWebEngineTestSupport *testSupport);
+#endif
+
 public Q_SLOTS:
     void runJavaScript(const QString&, const QJSValue & = QJSValue());
     void loadHtml(const QString &html, const QUrl &baseUrl = QUrl());
diff --git a/src/webengine/api/qquickwebengineview_p_p.h b/src/webengine/api/qquickwebengineview_p_p.h
index 7a33605de..6d9b16d70 100644
--- a/src/webengine/api/qquickwebengineview_p_p.h
+++ b/src/webengine/api/qquickwebengineview_p_p.h
@@ -57,6 +57,10 @@ class QQmlComponent;
 class QQmlContext;
 class QQuickWebEngineSettings;
 
+#ifdef ENABLE_QML_TESTSUPPORT_API
+class QQuickWebEngineTestSupport;
+#endif
+
 class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineViewport : public QObject {
     Q_OBJECT
     Q_PROPERTY(qreal devicePixelRatio READ devicePixelRatio WRITE setDevicePixelRatio NOTIFY devicePixelRatioChanged)
@@ -137,10 +141,10 @@ public:
     virtual void selectionChanged() Q_DECL_OVERRIDE { }
     virtual QRectF viewportRect() const Q_DECL_OVERRIDE;
     virtual qreal dpiScale() const Q_DECL_OVERRIDE;
-    virtual void loadStarted(const QUrl &provisionalUrl) Q_DECL_OVERRIDE;
+    virtual void loadStarted(const QUrl &provisionalUrl, bool isErrorPage = false) Q_DECL_OVERRIDE;
     virtual void loadCommitted() Q_DECL_OVERRIDE;
     virtual void loadVisuallyCommitted() Q_DECL_OVERRIDE;
-    virtual void loadFinished(bool success, const QUrl &url, int errorCode = 0, const QString &errorDescription = QString()) Q_DECL_OVERRIDE;
+    virtual void loadFinished(bool success, const QUrl &url, bool isErrorPage = false, int errorCode = 0, const QString &errorDescription = QString()) Q_DECL_OVERRIDE;
     virtual void focusContainer() Q_DECL_OVERRIDE;
     virtual void unhandledKeyEvent(QKeyEvent *event) Q_DECL_OVERRIDE;
     virtual void adoptNewWindow(QtWebEngineCore::WebContentsAdapter *newWebContents, WindowOpenDisposition disposition, bool userGesture, const QRect &) Q_DECL_OVERRIDE;
@@ -186,6 +190,9 @@ public:
     QScopedPointer<QQuickWebEngineHistory> m_history;
     QQuickWebEngineProfile *m_profile;
     QScopedPointer<QQuickWebEngineSettings> m_settings;
+#ifdef ENABLE_QML_TESTSUPPORT_API
+    QQuickWebEngineTestSupport *m_testSupport;
+#endif
     QQmlComponent *contextMenuExtraItems;
     QUrl explicitUrl;
     QUrl icon;
diff --git a/src/webengine/plugin/testsupport/plugin.cpp b/src/webengine/plugin/testsupport/plugin.cpp
new file mode 100644
index 000000000..60e56062c
--- /dev/null
+++ b/src/webengine/plugin/testsupport/plugin.cpp
@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtQml>
+
+#include "qquickwebenginetestsupport_p.h"
+
+QT_BEGIN_NAMESPACE
+
+class QtWebEngineTestSupportPlugin : public QQmlExtensionPlugin
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QQmlExtensionInterface/1.0")
+public:
+    virtual void registerTypes(const char *uri)
+    {
+        qWarning("\nWARNING: This project is using the testsupport QML API extensions for QtWebEngine and is therefore tied to a specific QtWebEngine release.\n"
+                 "WARNING: The testsupport API will change from version to version, or even be removed. You have been warned!\n");
+
+        Q_ASSERT(QLatin1String(uri) == QLatin1String("QtWebEngine.testsupport"));
+
+        qmlRegisterType<QQuickWebEngineTestSupport>(uri, 1, 0, "WebEngineTestSupport");
+        qmlRegisterUncreatableType<QQuickWebEngineErrorPage>(uri, 1, 0, "WebEngineErrorPage",
+            QObject::tr("Cannot create a separate instance of WebEngineErrorPage"));
+    }
+};
+
+QT_END_NAMESPACE
+
+#include "plugin.moc"
diff --git a/src/webengine/plugin/testsupport/qmldir b/src/webengine/plugin/testsupport/qmldir
new file mode 100644
index 000000000..588c9d2d4
--- /dev/null
+++ b/src/webengine/plugin/testsupport/qmldir
@@ -0,0 +1,3 @@
+module QtWebEngine.testsupport
+plugin qtwebenginetestsupportplugin
+typeinfo plugins.qmltypes
diff --git a/src/webengine/plugin/testsupport/testsupport.pro b/src/webengine/plugin/testsupport/testsupport.pro
new file mode 100644
index 000000000..1a45ad56a
--- /dev/null
+++ b/src/webengine/plugin/testsupport/testsupport.pro
@@ -0,0 +1,13 @@
+CXX_MODULE = qml
+TARGET = qtwebenginetestsupportplugin
+TARGETPATH = QtWebEngine/testsupport
+IMPORT_VERSION = 1.0
+
+QT += webengine qml quick
+QT_PRIVATE += webengine-private
+
+INCLUDEPATH += $$QTWEBENGINE_ROOT/src/core $$QTWEBENGINE_ROOT/src/webengine $$QTWEBENGINE_ROOT/src/webengine/api
+
+SOURCES = plugin.cpp
+
+load(qml_plugin)
diff --git a/src/webengine/webengine.pro b/src/webengine/webengine.pro
index 154286e9e..6cba9c5d9 100644
--- a/src/webengine/webengine.pro
+++ b/src/webengine/webengine.pro
@@ -48,4 +48,11 @@ HEADERS = \
         render_widget_host_view_qt_delegate_quickwindow.h \
         ui_delegates_manager.h
 
+isQMLTestSupportApiEnabled() {
+    SOURCES += api/qquickwebenginetestsupport.cpp
+    HEADERS += api/qquickwebenginetestsupport_p.h
+
+    DEFINES += ENABLE_QML_TESTSUPPORT_API
+}
+
 load(qt_module)
diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index f4ec57342..7eab1dc71 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -242,10 +242,14 @@ qreal QWebEnginePagePrivate::dpiScale() const
     return 1.0;
 }
 
-void QWebEnginePagePrivate::loadStarted(const QUrl &provisionalUrl)
+void QWebEnginePagePrivate::loadStarted(const QUrl &provisionalUrl, bool isErrorPage)
 {
-    Q_UNUSED(provisionalUrl)
+    Q_UNUSED(provisionalUrl);
     Q_Q(QWebEnginePage);
+
+    if (isErrorPage)
+        return;
+
     isLoading = true;
     Q_EMIT q->loadStarted();
     updateNavigationActions();
@@ -256,12 +260,16 @@ void QWebEnginePagePrivate::loadCommitted()
     updateNavigationActions();
 }
 
-void QWebEnginePagePrivate::loadFinished(bool success, const QUrl &url, int errorCode, const QString &errorDescription)
+void QWebEnginePagePrivate::loadFinished(bool success, const QUrl &url, bool isErrorPage, int errorCode, const QString &errorDescription)
 {
     Q_Q(QWebEnginePage);
     Q_UNUSED(url);
     Q_UNUSED(errorCode);
     Q_UNUSED(errorDescription);
+
+    if (isErrorPage)
+        return;
+
     isLoading = false;
     if (success)
         explicitUrl = QUrl();
diff --git a/src/webenginewidgets/api/qwebenginepage_p.h b/src/webenginewidgets/api/qwebenginepage_p.h
index b6da844d8..087137a78 100644
--- a/src/webenginewidgets/api/qwebenginepage_p.h
+++ b/src/webenginewidgets/api/qwebenginepage_p.h
@@ -118,10 +118,10 @@ public:
     virtual void selectionChanged() Q_DECL_OVERRIDE;
     virtual QRectF viewportRect() const Q_DECL_OVERRIDE;
     virtual qreal dpiScale() const Q_DECL_OVERRIDE;
-    virtual void loadStarted(const QUrl &provisionalUrl) Q_DECL_OVERRIDE;
+    virtual void loadStarted(const QUrl &provisionalUrl, bool isErrorPage = false) Q_DECL_OVERRIDE;
     virtual void loadCommitted() Q_DECL_OVERRIDE;
     virtual void loadVisuallyCommitted() Q_DECL_OVERRIDE { }
-    virtual void loadFinished(bool success, const QUrl &url, int errorCode = 0, const QString &errorDescription = QString()) Q_DECL_OVERRIDE;
+    virtual void loadFinished(bool success, const QUrl &url, bool isErrorPage = false, int errorCode = 0, const QString &errorDescription = QString()) Q_DECL_OVERRIDE;
     virtual void focusContainer() Q_DECL_OVERRIDE;
     virtual void unhandledKeyEvent(QKeyEvent *event) Q_DECL_OVERRIDE;
     virtual void adoptNewWindow(QtWebEngineCore::WebContentsAdapter *newWebContents, WindowOpenDisposition disposition, bool userGesture, const QRect &initialGeometry) Q_DECL_OVERRIDE;
diff --git a/tests/auto/quick/qmltests/data/tst_loadFail.qml b/tests/auto/quick/qmltests/data/tst_loadFail.qml
index e88d82903..7b5bbe2e2 100644
--- a/tests/auto/quick/qmltests/data/tst_loadFail.qml
+++ b/tests/auto/quick/qmltests/data/tst_loadFail.qml
@@ -43,36 +43,69 @@ import QtQuick 2.0
 import QtTest 1.0
 import QtWebEngine 1.1
 import QtWebEngine.experimental 1.0
+import QtWebEngine.testsupport 1.0
 
 TestWebEngineView {
     id: webEngineView
     width: 400
     height: 300
 
-    property variant unavailableUrl
+    property var unavailableUrl: Qt.resolvedUrl("file_that_does_not_exist.html")
+    property var loadRequestArray: []
+
+    testSupport: WebEngineTestSupport {
+        property var errorPageLoadStatus: null
+
+        function waitForErrorPageLoadSucceeded() {
+            var success = _waitFor(function() { return testSupport.errorPageLoadStatus == WebEngineView.LoadSucceededStatus })
+            testSupport.errorPageLoadStatus = null
+            return success
+        }
+
+        errorPage.onLoadingChanged: {
+            errorPageLoadStatus = loadRequest.status
+
+            loadRequestArray.push({
+               "status": loadRequest.status,
+               "url": loadRequest.url.toString(),
+               "errorDomain": loadRequest.errorDomain,
+               "isErrorPage": true
+            })
+        }
+    }
+
+    onLoadingChanged: {
+        if (loadRequest.status == WebEngineView.LoadFailedStatus) {
+            test.compare(loadRequest.url, unavailableUrl)
+            test.compare(loadRequest.errorDomain, WebEngineView.InternalErrorDomain)
+        }
+
+        loadRequestArray.push({
+           "status": loadRequest.status,
+           "url": loadRequest.url.toString(),
+           "errorDomain": loadRequest.errorDomain,
+           "isErrorPage": false
+        })
+    }
 
     TestCase {
         id: test
         name: "WebEngineViewLoadFail"
 
-        function initTestCase() {
-            WebEngine.settings.errorPageEnabled = false
-        }
-
         function test_fail() {
-            unavailableUrl = Qt.resolvedUrl("file_that_does_not_exist.html")
+            WebEngine.settings.errorPageEnabled = false
             webEngineView.url = unavailableUrl
             verify(webEngineView.waitForLoadFailed())
         }
 
         function test_fail_url() {
+            WebEngine.settings.errorPageEnabled = false
             var url = Qt.resolvedUrl("test1.html")
             webEngineView.url = url
             compare(webEngineView.url, url)
             verify(webEngineView.waitForLoadSucceeded())
             compare(webEngineView.url, url)
 
-            unavailableUrl = Qt.resolvedUrl("file_that_does_not_exist.html")
             webEngineView.url = unavailableUrl
             compare(webEngineView.url, unavailableUrl)
             verify(webEngineView.waitForLoadFailed())
@@ -80,12 +113,47 @@ TestWebEngineView {
             // We expect the url of the previously loaded page here.
             compare(webEngineView.url, url)
         }
-    }
 
-    onLoadingChanged: {
-        if (loadRequest.status == WebEngineView.LoadFailedStatus) {
-            test.compare(loadRequest.url, unavailableUrl)
-            test.compare(loadRequest.errorDomain, WebEngineView.InternalErrorDomain)
+        function test_error_page() {
+            WebEngine.settings.errorPageEnabled = true
+            webEngineView.url = unavailableUrl
+
+            // Loading of the error page must be successful
+            verify(webEngineView.testSupport.waitForErrorPageLoadSucceeded())
+
+            var loadRequest = null
+            compare(loadRequestArray.length, 4)
+
+            // Start to load unavailableUrl
+            loadRequest = loadRequestArray[0]
+            compare(loadRequest.status, WebEngineView.LoadStartedStatus)
+            compare(loadRequest.errorDomain, WebEngineView.NoErrorDomain)
+            compare(loadRequest.url, unavailableUrl)
+            verify(!loadRequest.isErrorPage)
+
+            // Loading of the unavailableUrl must fail
+            loadRequest = loadRequestArray[1]
+            compare(loadRequest.status, WebEngineView.LoadFailedStatus)
+            compare(loadRequest.errorDomain, WebEngineView.InternalErrorDomain)
+            compare(loadRequest.url, unavailableUrl)
+            verify(!loadRequest.isErrorPage)
+
+            // Start to load error page
+            loadRequest = loadRequestArray[2]
+            compare(loadRequest.status, WebEngineView.LoadStartedStatus)
+            compare(loadRequest.errorDomain, WebEngineView.NoErrorDomain)
+            compare(loadRequest.url, "data:text/html,chromewebdata")
+            verify(loadRequest.isErrorPage)
+
+            // Loading of the error page must be successful
+            loadRequest = loadRequestArray[3]
+            compare(loadRequest.status, WebEngineView.LoadSucceededStatus)
+            compare(loadRequest.errorDomain, WebEngineView.NoErrorDomain)
+            compare(loadRequest.url, "data:text/html,chromewebdata")
+            verify(loadRequest.isErrorPage)
+
+            compare(webEngineView.url, unavailableUrl)
+            compare(webEngineView.title, unavailableUrl + " is not found")
         }
     }
 }
diff --git a/tests/auto/quick/qmltests/qmltests.pro b/tests/auto/quick/qmltests/qmltests.pro
index 6789b714b..b71f1beb6 100644
--- a/tests/auto/quick/qmltests/qmltests.pro
+++ b/tests/auto/quick/qmltests/qmltests.pro
@@ -37,3 +37,22 @@ OTHER_FILES += \
 
 load(qt_build_paths)
 DEFINES += QUICK_TEST_SOURCE_DIR=\"\\\"$$PWD$${QMAKE_DIR_SEP}data\\\"\"
+
+!isQMLTestSupportApiEnabled() {
+    PLUGIN_EXTENSION = .so
+    PLUGIN_PREFIX = lib
+    osx: PLUGIN_PREFIX = .dylib
+    win32 {
+        PLUGIN_EXTENSION = .dll
+        PLUGIN_PREFIX =
+    }
+
+    TESTSUPPORT_MODULE = $$shell_path($$[QT_INSTALL_QML]/QtWebEngine/testsupport/$${PLUGIN_PREFIX}qtwebenginetestsupportplugin$${PLUGIN_EXTENSION})
+    BUILD_DIR = $$shell_path($$clean_path($$OUT_PWD/../../../..))
+    SRC_DIR = $$shell_path($$clean_path($$PWD/../../../..))
+
+    warning("QML Test Support API is disabled. This means some QML tests that use Test Support API will fail.")
+    warning("Use the following command to build Test Support module and rebuild WebEngineView API:")
+    warning("cd $$BUILD_DIR && qmake WEBENGINE_CONFIG+=testsupport -r $$shell_path($$SRC_DIR/qtwebengine.pro) && make -C $$shell_path($$BUILD_DIR/src/webengine) clean && make")
+    warning("After performing the command above make sure QML module \"QtWebEngine.testsupport\" is deployed at $$TESTSUPPORT_MODULE")
+}
diff --git a/tools/qmake/mkspecs/features/functions.prf b/tools/qmake/mkspecs/features/functions.prf
index 2e2261cb9..a34bd23c6 100644
--- a/tools/qmake/mkspecs/features/functions.prf
+++ b/tools/qmake/mkspecs/features/functions.prf
@@ -37,6 +37,12 @@ defineTest(isGCCVersionSupported) {
   return(false)
 }
 
+defineTest(isQMLTestSupportApiEnabled) {
+    contains(QT_BUILD_PARTS, tests): return(true)
+    contains(WEBENGINE_CONFIG, testsupport): return(true)
+    return(false)
+}
+
 # Map to the correct target type for gyp
 defineReplace(toGypTargetType) {
   equals(TEMPLATE, "app"):return("executable")