Added parseShorthand method from the parser to CSSPropertyAPI.h.

third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h

Index: third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
diff --git a/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
index 66b49c1d847ce8648f210b6f4cb9f3478f68e1eb..0280eb94863d2d3b745c8897518171730a5adf54 100644
--- a/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
+++ b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPI.h
@@ -41,6 +41,15 @@ class CSSPropertyAPI {
     NOTREACHED();
     return nullptr;
   }
+
+  static bool parseShorthand(bool,
+                             CSSParserTokenRange&,
+                             const CSSParserContext*) {
+    // No code should reach here, since properties either have their own
+    // implementations of this method or store nullptr in their descriptor.
+    NOTREACHED();
+    return false;
+  }
 };
 
 }  // namespace blink