3 files changed, 11 insertions, 7 deletions
diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index f1c69fca3..f96329139 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -422,7 +422,7 @@ void RenderWidgetHostViewQt::SetBackgroundColor(SkColor color)
 bool RenderWidgetHostViewQt::LockMouse()
 {
     mouse_locked_ = true;
-    m_lockedMousePosition = QCursor::pos();
+    m_previousMousePosition = QCursor::pos();
     m_delegate->lockMouse();
     qApp->setOverrideCursor(Qt::BlankCursor);
     return true;
@@ -938,11 +938,13 @@ void RenderWidgetHostViewQt::handleMouseEvent(QMouseEvent* event)
         m_clickHelper.lastPressPosition = QPointF(event->pos()).toPoint();
     }
 
-    if (IsMouseLocked()) {
-        webEvent.movementX = -(m_lockedMousePosition.x() - event->globalX());
-        webEvent.movementY = -(m_lockedMousePosition.y() - event->globalY());
-        QCursor::setPos(m_lockedMousePosition);
-    }
+    webEvent.movementX = event->globalX() - m_previousMousePosition.x();
+    webEvent.movementY = event->globalY() - m_previousMousePosition.y();
+
+    if (IsMouseLocked())
+        QCursor::setPos(m_previousMousePosition);
+    else
+        m_previousMousePosition = event->globalPos();
 
     if (m_imeInProgress && event->type() == QMouseEvent::MouseButtonPress) {
         m_imeInProgress = false;
diff --git a/src/core/render_widget_host_view_qt.h b/src/core/render_widget_host_view_qt.h
index 8871d88ce..1dae96a53 100644
--- a/src/core/render_widget_host_view_qt.h
+++ b/src/core/render_widget_host_view_qt.h
@@ -242,7 +242,7 @@ private:
     ui::TextInputType m_currentInputType;
     bool m_imeInProgress;
     bool m_receivedEmptyImeText;
-    QPoint m_lockedMousePosition;
+    QPoint m_previousMousePosition;
 
     bool m_initPending;
 
diff --git a/src/core/web_event_factory.cpp b/src/core/web_event_factory.cpp
index ff5cc99a8..2cd15aa58 100644
--- a/src/core/web_event_factory.cpp
+++ b/src/core/web_event_factory.cpp
@@ -1205,6 +1205,8 @@ WebMouseEvent WebEventFactory::toWebMouseEvent(QHoverEvent *ev, double dpiScale)
 
     webKitEvent.x = webKitEvent.windowX = ev->pos().x() / dpiScale;
     webKitEvent.y = webKitEvent.windowY = ev->pos().y() / dpiScale;
+    webKitEvent.movementX = ev->pos().x() - ev->oldPos().x();
+    webKitEvent.movementY = ev->pos().y() - ev->oldPos().y();
 
     webKitEvent.type = webEventTypeForEvent(ev);
     return webKitEvent;