Fix a crash when attempting to drag

Q_UNREACHABLE in RenderWidgetHostViewQt::GetNativeView is now called
through RenderViewHostImpl::OnStartDragging since the last Chromium
update.

Even after removing this, OnStartDragging will now also try fetching
the device pixel ratio through gfx::Screen::GetNativeScreen().

Provide a dummy implementation of gfx::Screen only to avoid the crash,
the class still doesn't do anything and is filled with Q_UNREACHABLEs
to catch if any of those methods are reached in a future Chromium
update.

Change-Id: I2e9dafab5e4622df97100dd7a859523067635118
Reviewed-by: Andras Becsi <andras.becsi@digia.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/src/core/desktop_screen_qt.h b/src/core/desktop_screen_qt.h
new file mode 100644
index 000000000..79eb9c8d5
--- /dev/null
+++ b/src/core/desktop_screen_qt.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef DESKTOP_SCREEN_QT_H
+#define DESKTOP_SCREEN_QT_H
+
+#include "ui/gfx/screen.h"
+
+#include <QtGlobal>
+
+class DesktopScreenQt : public gfx::Screen {
+public:
+    // Overridden from gfx::Screen:
+    virtual bool IsDIPEnabled() Q_DECL_OVERRIDE;
+    virtual gfx::Point GetCursorScreenPoint() Q_DECL_OVERRIDE;
+    virtual gfx::NativeWindow GetWindowUnderCursor() Q_DECL_OVERRIDE;
+    virtual gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) Q_DECL_OVERRIDE;
+    virtual int GetNumDisplays() const Q_DECL_OVERRIDE;
+    virtual std::vector<gfx::Display> GetAllDisplays() const Q_DECL_OVERRIDE;
+    virtual gfx::Display GetDisplayNearestWindow(gfx::NativeView window) const Q_DECL_OVERRIDE;
+    virtual gfx::Display GetDisplayNearestPoint(const gfx::Point& point) const Q_DECL_OVERRIDE;
+    virtual gfx::Display GetDisplayMatching(const gfx::Rect& match_rect) const Q_DECL_OVERRIDE;
+    virtual gfx::Display GetPrimaryDisplay() const Q_DECL_OVERRIDE;
+    virtual void AddObserver(gfx::DisplayObserver* observer) Q_DECL_OVERRIDE;
+    virtual void RemoveObserver(gfx::DisplayObserver* observer) Q_DECL_OVERRIDE;
+};
+
+#endif // DESKTOP_SCREEN_QT_H