Adds HostResolveImpl Requests and Jobs to log.

net/base/net_log.h

Index: net/base/net_log.h
===================================================================
--- net/base/net_log.h	(revision 57182)
+++ net/base/net_log.h	(working copy)
@@ -70,8 +70,11 @@
 
     Source() : type(SOURCE_NONE), id(kInvalidId) {}
     Source(SourceType type, uint32 id) : type(type), id(id) {}
-    bool is_valid() { return id != kInvalidId; }
+    bool is_valid() const { return id != kInvalidId; }
 
+    // The caller takes ownership of the returned Value*.
+    Value* ToValue() const;
+
     SourceType type;
     uint32 id;
   };