Bounds check the zoom factor before we pass it along.

As it turns out failing to do so can mess up the page state.

Change-Id: I8cc785b01c73bde5443bdb78554d7b3809d96afe
Reviewed-by: Andras Becsi <andras.becsi@digia.com>

src/core/web_contents_adapter.cpp

@@ -612,6 +612,8 @@ void WebContentsAdapter::serializeNavigationHistory(QDataStream &output)
 void WebContentsAdapter::setZoomFactor(qreal factor)
 {
     Q_D(WebContentsAdapter);
+    if (factor < content::kMinimumZoomFactor || factor > content::kMaximumZoomFactor)
+        return;
     content::HostZoomMap::SetZoomLevel(d->webContents.get(), content::ZoomFactorToZoomLevel(static_cast<double>(factor)));
 }