DebugVisualizers: Add blink::Length

tools/win/DebugVisualizers/webkit.natvis

 <?xml version="1.0" encoding="utf-8" ?>
 <AutoVisualizer
     xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
   <Type Name="WTF::String">
     <DisplayString Condition="m_impl.m_ptr == 0">(null)</DisplayString>
     <DisplayString IncludeView="bare">{*m_impl.m_ptr,view(bare)}</DisplayString>
     <DisplayString>{*m_impl.m_ptr}</DisplayString>
     <Expand>
       <Item Name="Impl">m_impl.m_ptr</Item>
     </Expand>
@@ skipping 69 matching lines @@
   </Type>
   <Type Name="blink::LayoutRect">
     <AlternativeType Name="blink::IntRect"/>
     <AlternativeType Name="blink::FloatRect"/>
     <DisplayString>({m_location.m_x}, {m_location.m_y}) x ({m_size.m_width}, {m_size.m_height})</DisplayString>
     <Expand>
       <Item Name="Location">m_location</Item>
       <Item Name="Size">m_size</Item>
     </Expand>
   </Type>
+  <Type Name="blink::Length">
+    <DisplayString Condition="m_isFloat">{(blink::LengthType)m_type} {m_floatValue}</DisplayString>
+    <DisplayString>{(blink::LengthType)m_type} {m_intValue}</DisplayString>
+  </Type>
   <Type Name="blink::WebRect">
     <AlternativeType Name="blink::WebFloatRect"/>
     <DisplayString>({x}, {y}) x ({width}, {height})</DisplayString>
     <Expand>
       <Item Name="x">x</Item>
       <Item Name="y">y</Item>
       <Item Name="width">width</Item>
       <Item Name="height">height</Item>
       <Synthetic Name="right">
         <DisplayString>{x + width}</DisplayString>
@@ skipping 88 matching lines @@
   <Type Name="blink::BidiRun">
     <DisplayString>{*m_object} {m_start}-{m_stop}</DisplayString>
   </Type>
   <!-- Fonts -->
   <Type Name="blink::SimpleFontData">
     <DisplayString>{m_platformData}</DisplayString>
   </Type>
   <Type Name="blink::FontPlatformData">
     <DisplayString>{*m_typeface.m_ptr}, {m_textSize}px</DisplayString>
   </Type>
-  <Type Name="LogFontTypeface">
-    <DisplayString>{fLogFont.lfFaceName,su}</DisplayString>
-  </Type>
 </AutoVisualizer>