Use a struct for cc::Surface ids for more type safety

cc/surfaces/surface_aggregator.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/surfaces/surface_aggregator.h"
 
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/delegated_frame_data.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/quads/surface_draw_quad.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 
 namespace cc {
 
 SurfaceAggregator::SurfaceAggregator(SurfaceManager* manager)
     : manager_(manager) {
   DCHECK(manager_);
 }
 
 SurfaceAggregator::~SurfaceAggregator() {}
 
-DelegatedFrameData* SurfaceAggregator::GetReferencedDataForSurfaceID(
-    int surface_id) {
-  Surface* referenced_surface = manager_->GetSurfaceForID(surface_id);
+DelegatedFrameData* SurfaceAggregator::GetReferencedDataForSurfaceId(
+    SurfaceId surface_id) {
+  Surface* referenced_surface = manager_->GetSurfaceForId(surface_id);
   if (!referenced_surface)
     return NULL;  // Invalid surface id, skip this quad.
   CompositorFrame* referenced_frame = referenced_surface->GetEligibleFrame();
   if (!referenced_frame)
     return NULL;
   return referenced_frame->delegated_frame_data.get();
 }
 
 class SurfaceAggregator::RenderPassIdAllocator {
  public:
@@ skipping 27 matching lines @@
   if (!allocator) {
     allocator = new RenderPassIdAllocator(surface_id);
     render_pass_allocator_map_.set(surface_id, make_scoped_ptr(allocator));
   }
   allocator->AddKnownPass(surface_local_pass_id);
   return allocator->Remap(surface_local_pass_id);
 }
 
 void SurfaceAggregator::HandleSurfaceQuad(const SurfaceDrawQuad* surface_quad,
                                           RenderPass* dest_pass) {
-  int surface_id = surface_quad->surface_id;
+  SurfaceId surface_id = surface_quad->surface_id;
   // If this surface's id is already in our referenced set then it creates
   // a cycle in the graph and should be dropped.
-  if (referenced_surfaces_.count(surface_id))
+  if (referenced_surfaces_.count(surface_id.id))
     return;
   DelegatedFrameData* referenced_data =
-      GetReferencedDataForSurfaceID(surface_id);
+      GetReferencedDataForSurfaceId(surface_id);
   if (!referenced_data)
     return;
-  std::set<int>::iterator it = referenced_surfaces_.insert(surface_id).first;
+  std::set<int>::iterator it = referenced_surfaces_.insert(surface_id.id).first;
 
   const RenderPassList& referenced_passes = referenced_data->render_pass_list;
   for (size_t j = 0; j + 1 < referenced_passes.size(); ++j) {
     const RenderPass& source = *referenced_passes[j];
 
     scoped_ptr<RenderPass> copy_pass(RenderPass::Create());
 
-    RenderPass::Id remapped_pass_id = RemapPassId(source.id, surface_id);
+    RenderPass::Id remapped_pass_id = RemapPassId(source.id, surface_id.id);
 
     copy_pass->SetAll(remapped_pass_id,
                       source.output_rect,
                       source.damage_rect,
                       source.transform_to_root_target,
                       source.has_transparent_background);
 
     // Contributing passes aggregated in to the pass list need to take the
     // transform of the surface quad into account to update their transform to
     // the root surface.
     // TODO(jamesr): Make sure this is sufficient for surfaces nested several
     // levels deep and add tests.
     copy_pass->transform_to_root_target.ConcatTransform(
         surface_quad->quadTransform());
 
     CopyQuadsToPass(source.quad_list,
                     source.shared_quad_state_list,
                     gfx::Transform(),
                     copy_pass.get(),
-                    surface_id);
+                    surface_id.id);
 
     dest_pass_list_->push_back(copy_pass.Pass());
   }
 
   // TODO(jamesr): Clean up last pass special casing.
   const RenderPass& last_pass = *referenced_data->render_pass_list.back();
   const QuadList& quads = last_pass.quad_list;
 
   // TODO(jamesr): Make sure clipping is enforced.
   CopyQuadsToPass(quads,
                   last_pass.shared_quad_state_list,
                   surface_quad->quadTransform(),
                   dest_pass,
-                  surface_id);
+                  surface_id.id);
 
   referenced_surfaces_.erase(it);
 }
 
 void SurfaceAggregator::CopySharedQuadState(
     const SharedQuadState* source_sqs,
     const gfx::Transform& content_to_target_transform,
     RenderPass* dest_render_pass) {
   SharedQuadState* copy_shared_quad_state =
       dest_render_pass->CreateAndAppendSharedQuadState();
@@ skipping 69 matching lines @@
     CopyQuadsToPass(source.quad_list,
                     source.shared_quad_state_list,
                     gfx::Transform(),
                     copy_pass.get(),
                     surface_id);
 
     dest_pass_list_->push_back(copy_pass.Pass());
   }
 }
 
-scoped_ptr<CompositorFrame> SurfaceAggregator::Aggregate(int surface_id) {
-  Surface* surface = manager_->GetSurfaceForID(surface_id);
+scoped_ptr<CompositorFrame> SurfaceAggregator::Aggregate(SurfaceId surface_id) {
+  Surface* surface = manager_->GetSurfaceForId(surface_id);
   if (!surface)
     return scoped_ptr<CompositorFrame>();
   CompositorFrame* root_surface_frame = surface->GetEligibleFrame();
   if (!root_surface_frame)
     return scoped_ptr<CompositorFrame>();
 
   scoped_ptr<CompositorFrame> frame(new CompositorFrame);
   frame->delegated_frame_data = make_scoped_ptr(new DelegatedFrameData);
 
   DCHECK(root_surface_frame->delegated_frame_data);
 
   const RenderPassList& source_pass_list =
       root_surface_frame->delegated_frame_data->render_pass_list;
 
-  std::set<int>::iterator it = referenced_surfaces_.insert(surface_id).first;
+  std::set<int>::iterator it = referenced_surfaces_.insert(surface_id.id).first;
 
   dest_pass_list_ = &frame->delegated_frame_data->render_pass_list;
-  CopyPasses(source_pass_list, surface_id);
+  CopyPasses(source_pass_list, surface_id.id);
 
   referenced_surfaces_.erase(it);
   DCHECK(referenced_surfaces_.empty());
 
   dest_pass_list_ = NULL;
 
   // TODO(jamesr): Aggregate all resource references into the returned frame's
   // resource list.
 
   return frame.Pass();
 }
 
 }  // namespace cc