Rename cc::ResourceProvider::ResourceId to cc::ResourceId and move it to its own file.

cc/surfaces/surface_resource_holder.cc

Index: cc/surfaces/surface_resource_holder.cc
diff --git a/cc/surfaces/surface_resource_holder.cc b/cc/surfaces/surface_resource_holder.cc
index 50d31a584eef0021a28b4fef9a24c2d0205ae79c..c257b6082eb9cd83a1795e3eee754e32dc38b208 100644
--- a/cc/surfaces/surface_resource_holder.cc
+++ b/cc/surfaces/surface_resource_holder.cc
@@ -49,7 +49,7 @@ void SurfaceResourceHolder::UnrefResources(
   for (ReturnedResourceArray::const_iterator it = resources.begin();
        it != resources.end();
        ++it) {
-    ResourceProvider::ResourceId id = it->id;
+    unsigned id = it->id;
     ResourceIdCountMap::iterator count_it = resource_id_use_count_map_.find(id);
     if (count_it == resource_id_use_count_map_.end())
       continue;