Avoid clobbering state in viewport tag initialization.

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 3a08cfb7e1398a606ce73915bb0c1b314137e08a..83dccc328cae5b967cd24fbeec54850047387add 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -3150,47 +3150,46 @@ void Document::maybeHandleHttpRefresh(const String& content, HttpRefreshType htt
     m_frame->navigationScheduler().scheduleRedirect(delay, refreshURL);
 }
 
-bool Document::shouldMergeWithLegacyDescription(ViewportDescription::Type origin)
+bool Document::shouldMergeWithLegacyDescription(ViewportDescription::Type origin) const
 {
     return settings() && settings()->viewportMetaMergeContentQuirk() && m_legacyViewportDescription.isMetaViewportType() && m_legacyViewportDescription.type == origin;
 }
 
 void Document::setViewportDescription(const ViewportDescription& viewportDescription)
 {
-    if (viewportDescription == m_viewportDescription)
-        return;
-
-    if (settings() && !settings()->viewportMetaEnabled() && viewportDescription.isLegacyViewportType())
-        return;
-
-    // The UA-defined min-width is used by the processing of legacy meta tags.
-    if (!viewportDescription.isSpecifiedByAuthor())
-        m_viewportDefaultMinWidth = viewportDescription.minWidth;
-
     if (viewportDescription.isLegacyViewportType()) {
+        if (viewportDescription == m_legacyViewportDescription)
+            return;
         m_legacyViewportDescription = viewportDescription;
-
-        // When no author style for @viewport is present, and a meta tag for defining
-        // the viewport is, apply the meta tag viewport instead of the UA styles.
-        if (m_viewportDescription.type == ViewportDescription::AuthorStyleSheet)
+    } else {
+        if (viewportDescription == m_viewportDescription)
             return;
         m_viewportDescription = viewportDescription;
-    } else {
-        // If the legacy viewport tag has higher priority than the cascaded @viewport
-        // descriptors, use the values from the legacy tag.
-        if (!shouldOverrideLegacyDescription(viewportDescription.type))
-            m_viewportDescription = m_legacyViewportDescription;
-        else
-            m_viewportDescription = viewportDescription;
+
+        // The UA-defined min-width is considered specifically by Android WebView quirks mode.
+        if (!viewportDescription.isSpecifiedByAuthor())
+            m_viewportDefaultMinWidth = viewportDescription.minWidth;
     }
 
     updateViewportDescription();
 }
 
+ViewportDescription Document::viewportDescription() const
+{
+    ViewportDescription appliedViewportDescription = m_viewportDescription;
+    bool viewportMetaEnabled = settings() && settings()->viewportMetaEnabled();
+    if (m_legacyViewportDescription.type != ViewportDescription::UserAgentStyleSheet && viewportMetaEnabled)
+        appliedViewportDescription = m_legacyViewportDescription;
+    if (shouldOverrideLegacyDescription(m_viewportDescription.type))
+        appliedViewportDescription = m_viewportDescription;
+
+    return appliedViewportDescription;
+}
+
 void Document::updateViewportDescription()
 {
     if (frame() && frame()->isMainFrame()) {
-        frameHost()->chromeClient().dispatchViewportPropertiesDidChange(m_viewportDescription);
+        frameHost()->chromeClient().dispatchViewportPropertiesDidChange(viewportDescription());
     }
 }