Translate viewport related meta tags into @viewport descriptors as suggested by the CSS Device Adap…

Source/core/rendering/RenderBox.cpp

Index: Source/core/rendering/RenderBox.cpp
diff --git a/Source/core/rendering/RenderBox.cpp b/Source/core/rendering/RenderBox.cpp
index 9950917073c88f88ab8fd742b8bc3cf5f935e724..369f603f4eeb8f1aac69fc5d9858f329eb9a706b 100644
--- a/Source/core/rendering/RenderBox.cpp
+++ b/Source/core/rendering/RenderBox.cpp
@@ -2752,7 +2752,7 @@ LayoutUnit RenderBox::computeReplacedLogicalWidthUsing(Length logicalWidth) cons
             return adjustContentBoxLogicalWidthForBoxSizing(valueForLength(logicalWidth, 0, view()));
         case FitContent:
         case FillAvailable:
-        case Percent: 
+        case Percent:
         case Calculated: {
             // FIXME: containingBlockLogicalWidthForContent() is wrong if the replaced element's block-flow is perpendicular to the
             // containing block's block-flow.
@@ -2771,6 +2771,7 @@ LayoutUnit RenderBox::computeReplacedLogicalWidthUsing(Length logicalWidth) cons
         case MinIntrinsic:
         case Auto:
         case Relative:
+        case ExtendToZoom:
         case Undefined:
             return intrinsicLogicalWidth();
     }