cc/surfaces/surface_aggregator.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/surfaces/surface_aggregator.h"
   6
   7 #include <map>
   8
   9 #include "base/bind.h"
  10 #include "base/containers/hash_tables.h"
  11 #include "base/logging.h"
  12 #include "base/trace_event/trace_event.h"
  13 #include "cc/base/math_util.h"
  14 #include "cc/output/compositor_frame.h"
  15 #include "cc/output/delegated_frame_data.h"
  16 #include "cc/quads/draw_quad.h"
  17 #include "cc/quads/render_pass_draw_quad.h"
  18 #include "cc/quads/shared_quad_state.h"
  19 #include "cc/quads/surface_draw_quad.h"
  20 #include "cc/surfaces/surface.h"
  21 #include "cc/surfaces/surface_factory.h"
  22 #include "cc/surfaces/surface_manager.h"
  23 #include "cc/trees/blocking_task_runner.h"
  24
  25 namespace cc {
  26 namespace {
  27
  28 void MoveMatchingRequests(
  29     RenderPassId id,
  30     std::multimap<RenderPassId, CopyOutputRequest*>* copy_requests,
  31     ScopedPtrVector<CopyOutputRequest>* output_requests) {
  32   auto request_range = copy_requests->equal_range(id);
  33   for (auto it = request_range.first; it != request_range.second; ++it) {
  34     DCHECK(it->second);
  35     output_requests->push_back(scoped_ptr<CopyOutputRequest>(it->second));
  36     it->second = nullptr;
  37   }
  38   copy_requests->erase(request_range.first, request_range.second);
  39 }
  40
  41 }  // namespace
  42
  43 SurfaceAggregator::SurfaceAggregator(SurfaceManager* manager,
  44                                      ResourceProvider* provider,
  45                                      bool aggregate_only_damaged)
  46     : manager_(manager),
  47       provider_(provider),
  48       next_render_pass_id_(1),
  49       aggregate_only_damaged_(aggregate_only_damaged) {
  50   DCHECK(manager_);
  51 }
  52
  53 SurfaceAggregator::~SurfaceAggregator() {}
  54
  55 // Create a clip rect for an aggregated quad from the original clip rect and
  56 // the clip rect from the surface it's on.
  57 SurfaceAggregator::ClipData SurfaceAggregator::CalculateClipRect(
  58     const ClipData& surface_clip,
  59     const ClipData& quad_clip,
  60     const gfx::Transform& target_transform) {
  61   ClipData out_clip;
  62   if (surface_clip.is_clipped)
  63     out_clip = surface_clip;
  64
  65   if (quad_clip.is_clipped) {
  66     // TODO(jamesr): This only works if target_transform maps integer
  67     // rects to integer rects.
  68     gfx::Rect final_clip =
  69         MathUtil::MapEnclosingClippedRect(target_transform, quad_clip.rect);
  70     if (out_clip.is_clipped)
  71       out_clip.rect.Intersect(final_clip);
  72     else
  73       out_clip.rect = final_clip;
  74     out_clip.is_clipped = true;
  75   }
  76
  77   return out_clip;
  78 }
  79
  80 class SurfaceAggregator::RenderPassIdAllocator {
  81  public:
  82   explicit RenderPassIdAllocator(int* next_index) : next_index_(next_index) {}
  83   ~RenderPassIdAllocator() {}
  84
  85   void AddKnownPass(RenderPassId id) {
  86     if (id_to_index_map_.find(id) != id_to_index_map_.end())
  87       return;
  88     id_to_index_map_[id] = (*next_index_)++;
  89   }
  90
  91   RenderPassId Remap(RenderPassId id) {
  92     DCHECK(id_to_index_map_.find(id) != id_to_index_map_.end());
  93     return RenderPassId(1, id_to_index_map_[id]);
  94   }
  95
  96  private:
  97   base::hash_map<RenderPassId, int> id_to_index_map_;
  98   int* next_index_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(RenderPassIdAllocator);
 101 };
 102
 103 static void UnrefHelper(base::WeakPtr<SurfaceFactory> surface_factory,
 104                         const ReturnedResourceArray& resources,
 105                         BlockingTaskRunner* main_thread_task_runner) {
 106   if (surface_factory)
 107     surface_factory->UnrefResources(resources);
 108 }
 109
 110 RenderPassId SurfaceAggregator::RemapPassId(RenderPassId surface_local_pass_id,
 111                                             SurfaceId surface_id) {
 112   RenderPassIdAllocator* allocator = render_pass_allocator_map_.get(surface_id);
 113   if (!allocator) {
 114     allocator = new RenderPassIdAllocator(&next_render_pass_id_);
 115     render_pass_allocator_map_.set(surface_id, make_scoped_ptr(allocator));
 116   }
 117   allocator->AddKnownPass(surface_local_pass_id);
 118   return allocator->Remap(surface_local_pass_id);
 119 }
 120
 121 int SurfaceAggregator::ChildIdForSurface(Surface* surface) {
 122   SurfaceToResourceChildIdMap::iterator it =
 123       surface_id_to_resource_child_id_.find(surface->surface_id());
 124   if (it == surface_id_to_resource_child_id_.end()) {
 125     int child_id =
 126         provider_->CreateChild(base::Bind(&UnrefHelper, surface->factory()));
 127     if (surface->factory()) {
 128       provider_->SetChildNeedsSyncPoints(
 129           child_id, surface->factory()->needs_sync_points());
 130     }
 131     surface_id_to_resource_child_id_[surface->surface_id()] = child_id;
 132     return child_id;
 133   } else {
 134     return it->second;
 135   }
 136 }
 137
 138
 139 gfx::Rect SurfaceAggregator::DamageRectForSurface(const Surface* surface,
 140                                                   const RenderPass& source,
 141                                                   const gfx::Rect& full_rect) {
 142   int previous_index = previous_contained_surfaces_[surface->surface_id()];
 143   if (previous_index == surface->frame_index())
 144     return gfx::Rect();
 145   else if (previous_index == surface->frame_index() - 1)
 146     return source.damage_rect;
 147   return full_rect;
 148 }
 149
 150 void SurfaceAggregator::HandleSurfaceQuad(
 151     const SurfaceDrawQuad* surface_quad,
 152     const gfx::Transform& target_transform,
 153     const ClipData& clip_rect,
 154     RenderPass* dest_pass) {
 155   SurfaceId surface_id = surface_quad->surface_id;
 156   // If this surface's id is already in our referenced set then it creates
 157   // a cycle in the graph and should be dropped.
 158   if (referenced_surfaces_.count(surface_id))
 159     return;
 160   Surface* surface = manager_->GetSurfaceForId(surface_id);
 161   if (!surface)
 162     return;
 163   const CompositorFrame* frame = surface->GetEligibleFrame();
 164   if (!frame)
 165     return;
 166   const DelegatedFrameData* frame_data = frame->delegated_frame_data.get();
 167   if (!frame_data)
 168     return;
 169
 170   std::multimap<RenderPassId, CopyOutputRequest*> copy_requests;
 171   surface->TakeCopyOutputRequests(&copy_requests);
 172
 173   const RenderPassList& render_pass_list = frame_data->render_pass_list;
 174   if (!valid_surfaces_.count(surface->surface_id())) {
 175     for (auto& request : copy_requests) {
 176       request.second->SendEmptyResult();
 177       delete request.second;
 178     }
 179     return;
 180   }
 181
 182   SurfaceSet::iterator it = referenced_surfaces_.insert(surface_id).first;
 183   // TODO(vmpstr): provider check is a hack for unittests that don't set up a
 184   // resource provider.
 185   ResourceProvider::ResourceIdMap empty_map;
 186   const ResourceProvider::ResourceIdMap& child_to_parent_map =
 187       provider_ ? provider_->GetChildToParentMap(ChildIdForSurface(surface))
 188                 : empty_map;
 189   bool merge_pass =
 190       surface_quad->shared_quad_state->opacity == 1.f && copy_requests.empty();
 191
 192   const RenderPassList& referenced_passes = render_pass_list;
 193   size_t passes_to_copy =
 194       merge_pass ? referenced_passes.size() - 1 : referenced_passes.size();
 195   for (size_t j = 0; j < passes_to_copy; ++j) {
 196     const RenderPass& source = *referenced_passes[j];
 197
 198     size_t sqs_size = source.shared_quad_state_list.size();
 199     size_t dq_size = source.quad_list.size();
 200     scoped_ptr<RenderPass> copy_pass(RenderPass::Create(sqs_size, dq_size));
 201
 202     RenderPassId remapped_pass_id = RemapPassId(source.id, surface_id);
 203
 204     copy_pass->SetAll(remapped_pass_id, source.output_rect, gfx::Rect(),
 205                       source.transform_to_root_target,
 206                       source.has_transparent_background);
 207
 208     MoveMatchingRequests(source.id, &copy_requests, &copy_pass->copy_requests);
 209
 210     // Contributing passes aggregated in to the pass list need to take the
 211     // transform of the surface quad into account to update their transform to
 212     // the root surface.
 213     copy_pass->transform_to_root_target.ConcatTransform(
 214         surface_quad->shared_quad_state->quad_to_target_transform);
 215     copy_pass->transform_to_root_target.ConcatTransform(target_transform);
 216     copy_pass->transform_to_root_target.ConcatTransform(
 217         dest_pass->transform_to_root_target);
 218
 219     CopyQuadsToPass(source.quad_list, source.shared_quad_state_list,
 220                     child_to_parent_map, gfx::Transform(), ClipData(),
 221                     copy_pass.get(), surface_id);
 222
 223     dest_pass_list_->push_back(copy_pass.Pass());
 224   }
 225
 226   gfx::Transform surface_transform =
 227       surface_quad->shared_quad_state->quad_to_target_transform;
 228   surface_transform.ConcatTransform(target_transform);
 229
 230   const RenderPass& last_pass = *render_pass_list.back();
 231   if (merge_pass) {
 232     // TODO(jamesr): Clean up last pass special casing.
 233     const QuadList& quads = last_pass.quad_list;
 234
 235     // Intersect the transformed visible rect and the clip rect to create a
 236     // smaller cliprect for the quad.
 237     ClipData surface_quad_clip_rect(
 238         true, MathUtil::MapEnclosingClippedRect(
 239                   surface_quad->shared_quad_state->quad_to_target_transform,
 240                   surface_quad->visible_rect));
 241     if (surface_quad->shared_quad_state->is_clipped) {
 242       surface_quad_clip_rect.rect.Intersect(
 243           surface_quad->shared_quad_state->clip_rect);
 244     }
 245
 246     ClipData quads_clip =
 247         CalculateClipRect(clip_rect, surface_quad_clip_rect, target_transform);
 248
 249     CopyQuadsToPass(quads, last_pass.shared_quad_state_list,
 250                     child_to_parent_map, surface_transform, quads_clip,
 251                     dest_pass, surface_id);
 252   } else {
 253     RenderPassId remapped_pass_id = RemapPassId(last_pass.id, surface_id);
 254
 255     SharedQuadState* shared_quad_state =
 256         CopySharedQuadState(surface_quad->shared_quad_state, target_transform,
 257                             clip_rect, dest_pass);
 258
 259     RenderPassDrawQuad* quad =
 260         dest_pass->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
 261     quad->SetNew(shared_quad_state,
 262                  surface_quad->rect,
 263                  surface_quad->visible_rect,
 264                  remapped_pass_id,
 265                  0,
 266                  gfx::Vector2dF(),
 267                  gfx::Size(),
 268                  FilterOperations(),
 269                  gfx::Vector2dF(),
 270                  FilterOperations());
 271   }
 272
 273   referenced_surfaces_.erase(it);
 274 }
 275
 276 SharedQuadState* SurfaceAggregator::CopySharedQuadState(
 277     const SharedQuadState* source_sqs,
 278     const gfx::Transform& target_transform,
 279     const ClipData& clip_rect,
 280     RenderPass* dest_render_pass) {
 281   SharedQuadState* copy_shared_quad_state =
 282       dest_render_pass->CreateAndAppendSharedQuadState();
 283   copy_shared_quad_state->CopyFrom(source_sqs);
 284   // target_transform contains any transformation that may exist
 285   // between the context that these quads are being copied from (i.e. the
 286   // surface's draw transform when aggregated from within a surface) to the
 287   // target space of the pass. This will be identity except when copying the
 288   // root draw pass from a surface into a pass when the surface draw quad's
 289   // transform is not identity.
 290   copy_shared_quad_state->quad_to_target_transform.ConcatTransform(
 291       target_transform);
 292
 293   ClipData new_clip_rect = CalculateClipRect(
 294       clip_rect, ClipData(source_sqs->is_clipped, source_sqs->clip_rect),
 295       target_transform);
 296   copy_shared_quad_state->is_clipped = new_clip_rect.is_clipped;
 297   copy_shared_quad_state->clip_rect = new_clip_rect.rect;
 298   return copy_shared_quad_state;
 299 }
 300
 301 static gfx::Rect CalculateQuadSpaceDamageRect(
 302     const gfx::Transform& quad_to_target_transform,
 303     const gfx::Transform& target_to_root_transform,
 304     const gfx::Rect& root_damage_rect) {
 305   gfx::Transform quad_to_root_transform(target_to_root_transform,
 306                                         quad_to_target_transform);
 307   gfx::Transform inverse_transform(gfx::Transform::kSkipInitialization);
 308   bool inverse_valid = quad_to_root_transform.GetInverse(&inverse_transform);
 309   DCHECK(inverse_valid);
 310
 311   return MathUtil::ProjectEnclosingClippedRect(inverse_transform,
 312                                                root_damage_rect);
 313 }
 314
 315 void SurfaceAggregator::CopyQuadsToPass(
 316     const QuadList& source_quad_list,
 317     const SharedQuadStateList& source_shared_quad_state_list,
 318     const ResourceProvider::ResourceIdMap& child_to_parent_map,
 319     const gfx::Transform& target_transform,
 320     const ClipData& clip_rect,
 321     RenderPass* dest_pass,
 322     SurfaceId surface_id) {
 323   const SharedQuadState* last_copied_source_shared_quad_state = nullptr;
 324   const SharedQuadState* dest_shared_quad_state = nullptr;
 325   // If the current frame has copy requests then aggregate the entire
 326   // thing, as otherwise parts of the copy requests may be ignored.
 327   const bool ignore_undamaged = aggregate_only_damaged_ && !has_copy_requests_;
 328   // Damage rect in the quad space of the current shared quad state.
 329   // TODO(jbauman): This rect may contain unnecessary area if
 330   // transform isn't axis-aligned.
 331   gfx::Rect damage_rect_in_quad_space;
 332
 333   SharedQuadStateList::ConstIterator sqs_iter =
 334       source_shared_quad_state_list.begin();
 335   for (const auto& quad : source_quad_list) {
 336     while (quad->shared_quad_state != *sqs_iter) {
 337       ++sqs_iter;
 338       DCHECK(sqs_iter != source_shared_quad_state_list.end());
 339     }
 340     DCHECK_EQ(quad->shared_quad_state, *sqs_iter);
 341
 342     if (quad->material == DrawQuad::SURFACE_CONTENT) {
 343       const SurfaceDrawQuad* surface_quad = SurfaceDrawQuad::MaterialCast(quad);
 344       // HandleSurfaceQuad may add other shared quad state, so reset the
 345       // current data.
 346       last_copied_source_shared_quad_state = nullptr;
 347
 348       if (ignore_undamaged) {
 349         gfx::Transform quad_to_target_transform(
 350             target_transform,
 351             quad->shared_quad_state->quad_to_target_transform);
 352         damage_rect_in_quad_space = CalculateQuadSpaceDamageRect(
 353             quad_to_target_transform, dest_pass->transform_to_root_target,
 354             root_damage_rect_);
 355         if (!damage_rect_in_quad_space.Intersects(quad->visible_rect))
 356           continue;
 357       }
 358       HandleSurfaceQuad(surface_quad, target_transform, clip_rect, dest_pass);
 359     } else {
 360       if (quad->shared_quad_state != last_copied_source_shared_quad_state) {
 361         dest_shared_quad_state = CopySharedQuadState(
 362             quad->shared_quad_state, target_transform, clip_rect, dest_pass);
 363         last_copied_source_shared_quad_state = quad->shared_quad_state;
 364         if (aggregate_only_damaged_ && !has_copy_requests_) {
 365           damage_rect_in_quad_space = CalculateQuadSpaceDamageRect(
 366               dest_shared_quad_state->quad_to_target_transform,
 367               dest_pass->transform_to_root_target, root_damage_rect_);
 368         }
 369       }
 370
 371       if (ignore_undamaged) {
 372         if (!damage_rect_in_quad_space.Intersects(quad->visible_rect))
 373           continue;
 374       }
 375
 376       DrawQuad* dest_quad;
 377       if (quad->material == DrawQuad::RENDER_PASS) {
 378         const RenderPassDrawQuad* pass_quad =
 379             RenderPassDrawQuad::MaterialCast(quad);
 380         RenderPassId original_pass_id = pass_quad->render_pass_id;
 381         RenderPassId remapped_pass_id =
 382             RemapPassId(original_pass_id, surface_id);
 383
 384         dest_quad = dest_pass->CopyFromAndAppendRenderPassDrawQuad(
 385             pass_quad, dest_shared_quad_state, remapped_pass_id);
 386       } else {
 387         dest_quad =
 388             dest_pass->CopyFromAndAppendDrawQuad(quad, dest_shared_quad_state);
 389       }
 390       if (!child_to_parent_map.empty()) {
 391         for (ResourceId& resource_id : dest_quad->resources) {
 392           ResourceProvider::ResourceIdMap::const_iterator it =
 393               child_to_parent_map.find(resource_id);
 394           DCHECK(it != child_to_parent_map.end());
 395
 396           DCHECK_EQ(it->first, resource_id);
 397           ResourceId remapped_id = it->second;
 398           resource_id = remapped_id;
 399         }
 400       }
 401     }
 402   }
 403 }
 404
 405 void SurfaceAggregator::CopyPasses(const DelegatedFrameData* frame_data,
 406                                    Surface* surface) {
 407   // The root surface is allowed to have copy output requests, so grab them
 408   // off its render passes.
 409   std::multimap<RenderPassId, CopyOutputRequest*> copy_requests;
 410   surface->TakeCopyOutputRequests(&copy_requests);
 411
 412   const RenderPassList& source_pass_list = frame_data->render_pass_list;
 413   DCHECK(valid_surfaces_.count(surface->surface_id()));
 414   if (!valid_surfaces_.count(surface->surface_id()))
 415     return;
 416
 417   // TODO(vmpstr): provider check is a hack for unittests that don't set up a
 418   // resource provider.
 419   ResourceProvider::ResourceIdMap empty_map;
 420   const ResourceProvider::ResourceIdMap& child_to_parent_map =
 421       provider_ ? provider_->GetChildToParentMap(ChildIdForSurface(surface))
 422                 : empty_map;
 423   for (size_t i = 0; i < source_pass_list.size(); ++i) {
 424     const RenderPass& source = *source_pass_list[i];
 425
 426     size_t sqs_size = source.shared_quad_state_list.size();
 427     size_t dq_size = source.quad_list.size();
 428     scoped_ptr<RenderPass> copy_pass(RenderPass::Create(sqs_size, dq_size));
 429
 430     MoveMatchingRequests(source.id, &copy_requests, &copy_pass->copy_requests);
 431
 432     RenderPassId remapped_pass_id =
 433         RemapPassId(source.id, surface->surface_id());
 434
 435     copy_pass->SetAll(remapped_pass_id, source.output_rect, gfx::Rect(),
 436                       source.transform_to_root_target,
 437                       source.has_transparent_background);
 438
 439     CopyQuadsToPass(source.quad_list, source.shared_quad_state_list,
 440                     child_to_parent_map, gfx::Transform(), ClipData(),
 441                     copy_pass.get(), surface->surface_id());
 442
 443     dest_pass_list_->push_back(copy_pass.Pass());
 444   }
 445 }
 446
 447 void SurfaceAggregator::RemoveUnreferencedChildren() {
 448   for (const auto& surface : previous_contained_surfaces_) {
 449     if (!contained_surfaces_.count(surface.first)) {
 450       SurfaceToResourceChildIdMap::iterator it =
 451           surface_id_to_resource_child_id_.find(surface.first);
 452       if (it != surface_id_to_resource_child_id_.end()) {
 453         provider_->DestroyChild(it->second);
 454         surface_id_to_resource_child_id_.erase(it);
 455       }
 456
 457       Surface* surface_ptr = manager_->GetSurfaceForId(surface.first);
 458       if (surface_ptr)
 459         surface_ptr->RunDrawCallbacks(SurfaceDrawStatus::DRAW_SKIPPED);
 460     }
 461   }
 462 }
 463
 464 // Walk the Surface tree from surface_id. Validate the resources of the current
 465 // surface and its descendants, check if there are any copy requests, and
 466 // return the combined damage rect.
 467 gfx::Rect SurfaceAggregator::PrewalkTree(SurfaceId surface_id) {
 468   if (referenced_surfaces_.count(surface_id))
 469     return gfx::Rect();
 470   Surface* surface = manager_->GetSurfaceForId(surface_id);
 471   if (!surface) {
 472     contained_surfaces_[surface_id] = 0;
 473     return gfx::Rect();
 474   }
 475   contained_surfaces_[surface_id] = surface->frame_index();
 476   const CompositorFrame* surface_frame = surface->GetEligibleFrame();
 477   if (!surface_frame)
 478     return gfx::Rect();
 479   const DelegatedFrameData* frame_data =
 480       surface_frame->delegated_frame_data.get();
 481   if (!frame_data)
 482     return gfx::Rect();
 483   int child_id = 0;
 484   // TODO(jbauman): hack for unit tests that don't set up rp
 485   if (provider_) {
 486     child_id = ChildIdForSurface(surface);
 487     if (surface->factory())
 488       surface->factory()->RefResources(frame_data->resource_list);
 489     provider_->ReceiveFromChild(child_id, frame_data->resource_list);
 490   }
 491
 492   ResourceProvider::ResourceIdSet referenced_resources;
 493   size_t reserve_size = frame_data->resource_list.size();
 494 #if defined(COMPILER_MSVC)
 495   referenced_resources.reserve(reserve_size);
 496 #elif defined(COMPILER_GCC)
 497   // Pre-standard hash-tables only implement resize, which behaves similarly
 498   // to reserve for these keys. Resizing to 0 may also be broken (particularly
 499   // on stlport).
 500   // TODO(jbauman): Replace with reserve when C++11 is supported everywhere.
 501   if (reserve_size)
 502     referenced_resources.resize(reserve_size);
 503 #endif
 504
 505   bool invalid_frame = false;
 506   ResourceProvider::ResourceIdMap empty_map;
 507   const ResourceProvider::ResourceIdMap& child_to_parent_map =
 508       provider_ ? provider_->GetChildToParentMap(child_id) : empty_map;
 509
 510   // Each pair in the vector is a child surface and the transform from its
 511   // target to the root target of this surface.
 512   std::vector<std::pair<SurfaceId, gfx::Transform>> child_surfaces;
 513   for (const auto& render_pass : frame_data->render_pass_list) {
 514     for (const auto& quad : render_pass->quad_list) {
 515       if (quad->material == DrawQuad::SURFACE_CONTENT) {
 516         const SurfaceDrawQuad* surface_quad =
 517             SurfaceDrawQuad::MaterialCast(quad);
 518         gfx::Transform target_to_surface_transform(
 519             render_pass->transform_to_root_target,
 520             surface_quad->shared_quad_state->quad_to_target_transform);
 521         child_surfaces.push_back(std::make_pair(surface_quad->surface_id,
 522                                                 target_to_surface_transform));
 523       }
 524
 525       if (!provider_)
 526         continue;
 527       for (ResourceId resource_id : quad->resources) {
 528         if (!child_to_parent_map.count(resource_id)) {
 529           invalid_frame = true;
 530           break;
 531         }
 532         referenced_resources.insert(resource_id);
 533       }
 534     }
 535   }
 536
 537   if (invalid_frame)
 538     return gfx::Rect();
 539   valid_surfaces_.insert(surface->surface_id());
 540
 541   if (provider_)
 542     provider_->DeclareUsedResourcesFromChild(child_id, referenced_resources);
 543
 544   for (const auto& render_pass : frame_data->render_pass_list)
 545     has_copy_requests_ |= !render_pass->copy_requests.empty();
 546
 547   gfx::Rect damage_rect;
 548   if (!frame_data->render_pass_list.empty()) {
 549     RenderPass* last_pass = frame_data->render_pass_list.back();
 550     damage_rect =
 551         DamageRectForSurface(surface, *last_pass, last_pass->output_rect);
 552   }
 553
 554   // Avoid infinite recursion by adding current surface to
 555   // referenced_surfaces_.
 556   SurfaceSet::iterator it =
 557       referenced_surfaces_.insert(surface->surface_id()).first;
 558   for (const auto& surface_info : child_surfaces) {
 559     gfx::Rect surface_damage = PrewalkTree(surface_info.first);
 560     damage_rect.Union(
 561         MathUtil::MapEnclosingClippedRect(surface_info.second, surface_damage));
 562   }
 563   referenced_surfaces_.erase(it);
 564   return damage_rect;
 565 }
 566
 567 scoped_ptr<CompositorFrame> SurfaceAggregator::Aggregate(SurfaceId surface_id) {
 568   Surface* surface = manager_->GetSurfaceForId(surface_id);
 569   DCHECK(surface);
 570   contained_surfaces_[surface_id] = surface->frame_index();
 571   const CompositorFrame* root_surface_frame = surface->GetEligibleFrame();
 572   if (!root_surface_frame)
 573     return nullptr;
 574   TRACE_EVENT0("cc", "SurfaceAggregator::Aggregate");
 575
 576   scoped_ptr<CompositorFrame> frame(new CompositorFrame);
 577   frame->delegated_frame_data = make_scoped_ptr(new DelegatedFrameData);
 578
 579   DCHECK(root_surface_frame->delegated_frame_data);
 580
 581   dest_resource_list_ = &frame->delegated_frame_data->resource_list;
 582   dest_pass_list_ = &frame->delegated_frame_data->render_pass_list;
 583
 584   valid_surfaces_.clear();
 585   has_copy_requests_ = false;
 586   root_damage_rect_ = PrewalkTree(surface_id);
 587
 588   SurfaceSet::iterator it = referenced_surfaces_.insert(surface_id).first;
 589   CopyPasses(root_surface_frame->delegated_frame_data.get(), surface);
 590   referenced_surfaces_.erase(it);
 591
 592   DCHECK(referenced_surfaces_.empty());
 593
 594   if (dest_pass_list_->empty())
 595     return nullptr;
 596   dest_pass_list_->back()->damage_rect = root_damage_rect_;
 597
 598   dest_pass_list_ = NULL;
 599   RemoveUnreferencedChildren();
 600   contained_surfaces_.swap(previous_contained_surfaces_);
 601   contained_surfaces_.clear();
 602
 603   for (SurfaceIndexMap::iterator it = previous_contained_surfaces_.begin();
 604        it != previous_contained_surfaces_.end();
 605        ++it) {
 606     Surface* surface = manager_->GetSurfaceForId(it->first);
 607     if (surface)
 608       surface->TakeLatencyInfo(&frame->metadata.latency_info);
 609   }
 610
 611   // TODO(jamesr): Aggregate all resource references into the returned frame's
 612   // resource list.
 613
 614   return frame.Pass();
 615 }
 616
 617 void SurfaceAggregator::ReleaseResources(SurfaceId surface_id) {
 618   SurfaceToResourceChildIdMap::iterator it =
 619       surface_id_to_resource_child_id_.find(surface_id);
 620   if (it != surface_id_to_resource_child_id_.end()) {
 621     provider_->DestroyChild(it->second);
 622     surface_id_to_resource_child_id_.erase(it);
 623   }
 624 }
 625
 626 void SurfaceAggregator::SetFullDamageForSurface(SurfaceId surface_id) {
 627   auto it = previous_contained_surfaces_.find(surface_id);
 628   if (it == previous_contained_surfaces_.end())
 629     return;
 630   // Set the last drawn index as 0 to ensure full damage next time it's drawn.
 631   it->second = 0;
 632 }
 633
 634 }  // namespace cc