Add 'XHR' to the Resource::Type enum, and use it for XHR requests.

Source/core/inspector/InspectorPageAgent.cpp

Index: Source/core/inspector/InspectorPageAgent.cpp
diff --git a/Source/core/inspector/InspectorPageAgent.cpp b/Source/core/inspector/InspectorPageAgent.cpp
index 7df66fff537faf4b7c98ff3d6454b99637d17882..427ebf9341d7249c11b1d87e107500fc9f5c7dd4 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -250,6 +250,7 @@ bool InspectorPageAgent::cachedResourceContent(Resource* cachedResource, String*
             return true;
         case Resource::MainResource:
             return false;
+        case Resource::XMLHttpRequest:
         case Resource::Raw: {
             SharedBuffer* buffer = cachedResource->resourceBuffer();
             if (!buffer)
@@ -353,6 +354,7 @@ InspectorPageAgent::ResourceType InspectorPageAgent::cachedResourceType(const Re
     case Resource::Script:
         return InspectorPageAgent::ScriptResource;
     case Resource::Raw:
+    case Resource::XMLHttpRequest:
         return InspectorPageAgent::XHRResource;
     case Resource::ImportResource:
         // Fall through.