Enable precompiled headers for Blink on Windows.

third_party/WebKit/Source/core/xml/XPathGrammar.y

Index: third_party/WebKit/Source/core/xml/XPathGrammar.y
diff --git a/third_party/WebKit/Source/core/xml/XPathGrammar.y b/third_party/WebKit/Source/core/xml/XPathGrammar.y
index bd3b1c15f2f6f7f0957285d4325abc2e8f0f833b..83836325e68cb485ab376ca4e295f72b74c725a7 100644
--- a/third_party/WebKit/Source/core/xml/XPathGrammar.y
+++ b/third_party/WebKit/Source/core/xml/XPathGrammar.y
@@ -394,14 +394,14 @@ PathExpr:
     FilterExpr '/' RelativeLocationPath
     {
         $3->setAbsolute(true);
-        $$ = new Path($1, $3);
+        $$ = new blink::XPath::Path($1, $3);
     }
     |
     FilterExpr DescendantOrSelf RelativeLocationPath
     {
         $3->insertFirstStep($2);
         $3->setAbsolute(true);
-        $$ = new Path($1, $3);
+        $$ = new blink::XPath::Path($1, $3);
     }
     ;
 
@@ -410,7 +410,7 @@ FilterExpr:
     |
     PrimaryExpr PredicateList
     {
-        $$ = new Filter($1, *$2);
+        $$ = new blink::XPath::Filter($1, *$2);
     }
     ;