Update viewport trigger for GPU rasterization

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 43ac7c71b38854b281b58948bfeb51e08b93aeef..c7bd60281f12277fc42607777511075a526ae111 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -2914,10 +2914,13 @@ void WebViewImpl::updatePageDefinedViewportConstraints(const ViewportDescription
 
     Document* document = page()->mainFrame()->document();
 
-    m_matchesHeuristicsForGpuRasterization = description.minimalUI
+    m_matchesHeuristicsForGpuRasterization = description.maxWidth == Length(DeviceWidth)
         && description.minZoom == 1.0
-        && description.minWidth == Length(ExtendToZoom)
-        && description.maxWidth == Length(DeviceWidth);
+        && description.minZoomIsExplicit
+        && description.zoom == 1.0
+        && description.zoomIsExplicit
+        && description.userZoom
+        && description.userZoomIsExplicit;
     if (m_layerTreeView)
         m_layerTreeView->heuristicsForGpuRasterizationUpdated(m_matchesHeuristicsForGpuRasterization);