Add ResourceType::PING. and mark those requests as detachable.

webkit/common/resource_type.h

Index: webkit/common/resource_type.h
diff --git a/webkit/common/resource_type.h b/webkit/common/resource_type.h
index d63c02c3d01d791baceb5ae4de4e0495fe7adec7..014a7224a2616b22cb42caa095a8d0603a432ccf 100644
--- a/webkit/common/resource_type.h
+++ b/webkit/common/resource_type.h
@@ -29,6 +29,7 @@ class ResourceType {
     PREFETCH,        // an explicitly requested prefetch
     FAVICON,         // a favicon
     XHR,             // a XMLHttpRequest
+    PING,            // a ping request for <a ping>
     LAST_TYPE        // Place holder so we don't need to change ValidType
                      // everytime.
   };