[Android WebView] Treat zero values in viewport arguments specially

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index fff83670193ce1dd38bab7914952d24d3abe66c2..0591f3a1bfb2e94189f0e61461a47abaa1970c24 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -2929,6 +2929,10 @@ void Document::processViewport(const String& features, ViewportArguments::Type o
     m_viewportArguments = ViewportArguments(origin);
     processArguments(features, (void*)&m_viewportArguments, &setViewportFeature);
 
+    if (page() && page()->settings().viewportMetaZeroValuesQuirk() && m_viewportArguments.type == ViewportArguments::ViewportMeta
+        && m_viewportArguments.width == ViewportArguments::ValueDeviceWidth && !static_cast<int>(m_viewportArguments.zoom))
+        m_viewportArguments.zoom = 1.0;
+
     updateViewportArguments();
 }