Don't ignore size updates that have a width and height == 0.

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index efd913d532715d009d0a117e2a97d1cd1b03c356..c41b624ae5b8057f4786d4bd05d5e1ce4fe67fd6 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -2858,7 +2858,7 @@ void WebViewImpl::refreshPageScaleFactorAfterLayout()
 
 void WebViewImpl::updatePageDefinedViewportConstraints(const ViewportDescription& description)
 {
-    if (!settings()->viewportEnabled() || !page() || !m_size.width || !m_size.height)
+    if (!settings()->viewportEnabled() || !page() || (!m_size.width && !m_size.height))
         return;
 
     ViewportDescription adjustedDescription = description;