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

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index a399d5ef35c323758b44c9989c982e95f48e9104..f75077da63a2f4824a17d6d37a44f078f784be5c 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -3286,7 +3286,7 @@ void LayerTreeHostImpl::CreateUIResource(UIResourceId uid,
 
   // Allow for multiple creation requests with the same UIResourceId.  The
   // previous resource is simply deleted.
-  ResourceProvider::ResourceId id = ResourceIdForUIResource(uid);
+  ResourceId id = ResourceIdForUIResource(uid);
   if (id)
     DeleteUIResource(uid);
 
@@ -3319,7 +3319,7 @@ void LayerTreeHostImpl::CreateUIResource(UIResourceId uid,
 }
 
 void LayerTreeHostImpl::DeleteUIResource(UIResourceId uid) {
-  ResourceProvider::ResourceId id = ResourceIdForUIResource(uid);
+  ResourceId id = ResourceIdForUIResource(uid);
   if (id) {
     resource_provider_->DeleteResource(id);
     ui_resource_map_.erase(uid);
@@ -3344,8 +3344,7 @@ void LayerTreeHostImpl::EvictAllUIResources() {
   client_->RenewTreePriority();
 }
 
-ResourceProvider::ResourceId LayerTreeHostImpl::ResourceIdForUIResource(
-    UIResourceId uid) const {
+ResourceId LayerTreeHostImpl::ResourceIdForUIResource(UIResourceId uid) const {
   UIResourceMap::const_iterator iter = ui_resource_map_.find(uid);
   if (iter != ui_resource_map_.end())
     return iter->second.resource_id;