Make RenderPass::Id an isolated class

cc/layers/delegated_renderer_layer_impl.cc

Index: cc/layers/delegated_renderer_layer_impl.cc
diff --git a/cc/layers/delegated_renderer_layer_impl.cc b/cc/layers/delegated_renderer_layer_impl.cc
index 9032fad7c98312c2f05982e55bc87470586aad81..199a15bbe7ddd78c25b1c538732018450a2a212f 100644
--- a/cc/layers/delegated_renderer_layer_impl.cc
+++ b/cc/layers/delegated_renderer_layer_impl.cc
@@ -165,7 +165,7 @@ void DelegatedRendererLayerImpl::SetRenderPasses(
     RenderPassList::iterator to_take =
         render_passes_in_draw_order->begin() + i;
     render_passes_index_by_id_.insert(
-        std::pair<RenderPass::Id, int>((*to_take)->id, i));
+        std::pair<RenderPassId, int>((*to_take)->id, i));
     scoped_ptr<RenderPass> taken_render_pass =
         render_passes_in_draw_order->take(to_take);
     render_passes_in_draw_order_.push_back(taken_render_pass.Pass());
@@ -194,20 +194,19 @@ void DelegatedRendererLayerImpl::ReleaseResources() {
 static inline int IndexToId(int index) { return index + 1; }
 static inline int IdToIndex(int id) { return id - 1; }
 
-RenderPass::Id DelegatedRendererLayerImpl::FirstContributingRenderPassId()
-    const {
-  return RenderPass::Id(id(), IndexToId(0));
+RenderPassId DelegatedRendererLayerImpl::FirstContributingRenderPassId() const {
+  return RenderPassId(id(), IndexToId(0));
 }
 
-RenderPass::Id DelegatedRendererLayerImpl::NextContributingRenderPassId(
-    RenderPass::Id previous) const {
-  return RenderPass::Id(previous.layer_id, previous.index + 1);
+RenderPassId DelegatedRendererLayerImpl::NextContributingRenderPassId(
+    RenderPassId previous) const {
+  return RenderPassId(previous.layer_id, previous.index + 1);
 }
 
 bool DelegatedRendererLayerImpl::ConvertDelegatedRenderPassId(
-    RenderPass::Id delegated_render_pass_id,
-    RenderPass::Id* output_render_pass_id) const {
-  base::hash_map<RenderPass::Id, int>::const_iterator found =
+    RenderPassId delegated_render_pass_id,
+    RenderPassId* output_render_pass_id) const {
+  base::hash_map<RenderPassId, int>::const_iterator found =
       render_passes_index_by_id_.find(delegated_render_pass_id);
   if (found == render_passes_index_by_id_.end()) {
     // Be robust against a RenderPass id that isn't part of the frame.
@@ -215,7 +214,7 @@ bool DelegatedRendererLayerImpl::ConvertDelegatedRenderPassId(
   }
   unsigned delegated_render_pass_index = found->second;
   *output_render_pass_id =
-      RenderPass::Id(id(), IndexToId(delegated_render_pass_index));
+      RenderPassId(id(), IndexToId(delegated_render_pass_index));
   return true;
 }
 
@@ -231,7 +230,7 @@ void DelegatedRendererLayerImpl::AppendContributingRenderPasses(
                                           inverse_device_scale_factor_);
 
   for (size_t i = 0; i < render_passes_in_draw_order_.size() - 1; ++i) {
-    RenderPass::Id output_render_pass_id(-1, -1);
+    RenderPassId output_render_pass_id(-1, -1);
     bool present =
         ConvertDelegatedRenderPassId(render_passes_in_draw_order_[i]->id,
                                      &output_render_pass_id);
@@ -266,7 +265,7 @@ void DelegatedRendererLayerImpl::AppendQuads(
   if (render_passes_in_draw_order_.empty())
     return;
 
-  RenderPass::Id target_render_pass_id = append_quads_data->render_pass_id;
+  RenderPassId target_render_pass_id = append_quads_data->render_pass_id;
 
   const RenderPass* root_delegated_render_pass =
       render_passes_in_draw_order_.back();
@@ -456,9 +455,9 @@ void DelegatedRendererLayerImpl::AppendRenderPassQuads(
           delegated_quad, output_shared_quad_state);
       output_quad->visible_rect = quad_visible_rect;
     } else {
-      RenderPass::Id delegated_contributing_render_pass_id =
+      RenderPassId delegated_contributing_render_pass_id =
           RenderPassDrawQuad::MaterialCast(delegated_quad)->render_pass_id;
-      RenderPass::Id output_contributing_render_pass_id(-1, -1);
+      RenderPassId output_contributing_render_pass_id(-1, -1);
 
       bool present =
           ConvertDelegatedRenderPassId(delegated_contributing_render_pass_id,