Use flat_set for ResourceIdSet

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 <stddef.h>
 
 #include <map>
 
@@ skipping 599 matching lines @@
   int child_id = 0;
   // TODO(jbauman): hack for unit tests that don't set up rp
   if (provider_) {
     child_id = ChildIdForSurface(surface);
     if (surface->factory())
       surface->factory()->RefResources(frame.resource_list);
     provider_->ReceiveFromChild(child_id, frame.resource_list);
   }
   CHECK(debug_weak_this.get());
 
-  ResourceIdSet referenced_resources;
+  std::vector<ResourceId> referenced_resources;
   size_t reserve_size = frame.resource_list.size();
   referenced_resources.reserve(reserve_size);
 
   bool invalid_frame = false;
   ResourceProvider::ResourceIdMap empty_map;
   const ResourceProvider::ResourceIdMap& child_to_parent_map =
       provider_ ? provider_->GetChildToParentMap(child_id) : empty_map;
 
   CHECK(debug_weak_this.get());
   if (!frame.render_pass_list.empty()) {
@@ skipping 63 matching lines @@
             RemapPassId(render_pass_quad->render_pass_id, surface_id));
       }
 
       if (!provider_)
         continue;
       for (ResourceId resource_id : quad->resources) {
         if (!child_to_parent_map.count(resource_id)) {
           invalid_frame = true;
           break;
         }
-        referenced_resources.insert(resource_id);
+        referenced_resources.push_back(resource_id);
       }
     }
   }
 
   if (invalid_frame)
     return gfx::Rect();
   CHECK(debug_weak_this.get());
   valid_surfaces_.insert(surface->surface_id());
 
+  ResourceIdSet resource_set(std::move(referenced_resources),
+                             base::KEEP_FIRST_OF_DUPES);
   if (provider_)
-    provider_->DeclareUsedResourcesFromChild(child_id, referenced_resources);
+    provider_->DeclareUsedResourcesFromChild(child_id, resource_set);
   CHECK(debug_weak_this.get());
 
   gfx::Rect damage_rect;
   gfx::Rect full_damage;
   if (!frame.render_pass_list.empty()) {
     RenderPass* last_pass = frame.render_pass_list.back().get();
     full_damage = last_pass->output_rect;
     damage_rect =
         DamageRectForSurface(surface, *last_pass, last_pass->output_rect);
   }
@@ skipping 203 matching lines @@
 }
 
 void SurfaceAggregator::SetOutputColorSpace(
     const gfx::ColorSpace& blending_color_space,
     const gfx::ColorSpace& output_color_space) {
   blending_color_space_ = blending_color_space;
   output_color_space_ = output_color_space;
 }
 
 }  // namespace cc