Read the default min-width value from the UA style sheets

Source/web/PageScaleConstraintsSet.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "PageScaleConstraintsSet.h"
 
+#include "platform/Length.h"
 #include "wtf/Assertions.h"
 
 using namespace WebCore;
 
 namespace blink {
 
 static const float defaultMinimumScale = 0.25f;
 static const float defaultMaximumScale = 5.0f;
 
 PageScaleConstraintsSet::PageScaleConstraintsSet()
     : m_lastContentsWidth(0)
     , m_needsReset(false)
     , m_constraintsDirty(false)
 {
     m_finalConstraints = defaultConstraints();
 }
 
 PageScaleConstraints PageScaleConstraintsSet::defaultConstraints() const
 {
     return PageScaleConstraints(-1, defaultMinimumScale, defaultMaximumScale);
 }
 
-void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, IntSize viewSize)
+void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, IntSize viewSize, Length legacyFallbackWidth)
 {
-    m_pageDefinedConstraints = description.resolve(viewSize);
+    m_pageDefinedConstraints = description.resolve(viewSize, legacyFallbackWidth);
 
     m_constraintsDirty = true;
 }
 
 void PageScaleConstraintsSet::setUserAgentConstraints(const PageScaleConstraints& userAgentConstraints)
 {
     m_userAgentConstraints = userAgentConstraints;
     m_constraintsDirty = true;
 }
 
@@ skipping 132 matching lines @@
             adjustedLayoutSizeWidth = viewSize.width() / targetDensityDPIFactor;
             adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, viewSize);
         }
     }
 
     m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
     m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
 }
 
 } // namespace WebCore