Make cc::CompositorFrames movable [Part 2 of 2]

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 170 matching lines @@
     const ClipData& clip_rect,
     RenderPass* dest_pass) {
   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))
     return;
   Surface* surface = manager_->GetSurfaceForId(surface_id);
   if (!surface)
     return;
-  const CompositorFrame* frame = surface->GetEligibleFrame();
-  if (!frame)
-    return;
-  const DelegatedFrameData* frame_data = frame->delegated_frame_data.get();
+  const CompositorFrame& frame = surface->GetEligibleFrame();
+  const DelegatedFrameData* frame_data = frame.delegated_frame_data.get();
   if (!frame_data)
     return;
 
   std::multimap<RenderPassId, std::unique_ptr<CopyOutputRequest>> copy_requests;
   surface->TakeCopyOutputRequests(&copy_requests);
 
   const RenderPassList& render_pass_list = frame_data->render_pass_list;
   if (!valid_surfaces_.count(surface->surface_id())) {
     for (auto& request : copy_requests)
       request.second->SendEmptyResult();
@@ skipping 351 matching lines @@
   base::WeakPtr<SurfaceAggregator> debug_weak_this = weak_factory_.GetWeakPtr();
 
   if (referenced_surfaces_.count(surface_id))
     return gfx::Rect();
   Surface* surface = manager_->GetSurfaceForId(surface_id);
   if (!surface) {
     contained_surfaces_[surface_id] = 0;
     return gfx::Rect();
   }
   contained_surfaces_[surface_id] = surface->frame_index();
-  const CompositorFrame* surface_frame = surface->GetEligibleFrame();
-  if (!surface_frame)
-    return gfx::Rect();
+  const CompositorFrame& surface_frame = surface->GetEligibleFrame();
   const DelegatedFrameData* frame_data =
-      surface_frame->delegated_frame_data.get();
+      surface_frame.delegated_frame_data.get();
   if (!frame_data)
     return gfx::Rect();
   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_data->resource_list);
     provider_->ReceiveFromChild(child_id, frame_data->resource_list);
   }
@@ skipping 99 matching lines @@
       // modified if there is a filter that moves pixels.
       damage_rect = full_damage;
       continue;
     }
 
     damage_rect.Union(MathUtil::MapEnclosingClippedRect(
         surface_info.target_to_surface_transform, surface_damage));
   }
 
   CHECK(debug_weak_this.get());
-  for (const auto& surface_id : surface_frame->metadata.referenced_surfaces) {
+  for (const auto& surface_id : surface_frame.metadata.referenced_surfaces) {
     if (!contained_surfaces_.count(surface_id)) {
       result->undrawn_surfaces.insert(surface_id);
       PrewalkTree(surface_id, false, RenderPassId(), result);
     }
   }
 
   CHECK(debug_weak_this.get());
   if (surface->factory())
     surface->factory()->WillDrawSurface(surface->surface_id(), damage_rect);
 
@@ skipping 16 matching lines @@
   // (or on Surfaces they reference) are executed.
   std::vector<SurfaceId> surfaces_to_copy(
       prewalk_result->undrawn_surfaces.begin(),
       prewalk_result->undrawn_surfaces.end());
 
   for (size_t i = 0; i < surfaces_to_copy.size(); i++) {
     SurfaceId surface_id = surfaces_to_copy[i];
     Surface* surface = manager_->GetSurfaceForId(surface_id);
     if (!surface)
       continue;
-    const CompositorFrame* surface_frame = surface->GetEligibleFrame();
-    if (!surface_frame)
+    const CompositorFrame& surface_frame = surface->GetEligibleFrame();
+    if (!surface_frame.delegated_frame_data)
       continue;
     bool surface_has_copy_requests = false;
     for (const auto& render_pass :
-         surface_frame->delegated_frame_data->render_pass_list) {
+         surface_frame.delegated_frame_data->render_pass_list) {
       surface_has_copy_requests |= !render_pass->copy_requests.empty();
     }
     if (!surface_has_copy_requests) {
       // Children are not necessarily included in undrawn_surfaces (because
       // they weren't referenced directly from a drawn surface), but may have
       // copy requests, so make sure to check them as well.
-      for (const auto& child_id : surface_frame->metadata.referenced_surfaces) {
+      for (const auto& child_id : surface_frame.metadata.referenced_surfaces) {
         // Don't iterate over the child Surface if it was already listed as a
         // child of a different Surface, or in the case where there's infinite
         // recursion.
         if (!prewalk_result->undrawn_surfaces.count(child_id)) {
           surfaces_to_copy.push_back(child_id);
           prewalk_result->undrawn_surfaces.insert(child_id);
         }
       }
     } else {
       SurfaceSet::iterator it = referenced_surfaces_.insert(surface_id).first;
-      CopyPasses(surface_frame->delegated_frame_data.get(), surface);
+      CopyPasses(surface_frame.delegated_frame_data.get(), surface);
       referenced_surfaces_.erase(it);
     }
   }
 }
 
 void SurfaceAggregator::PropagateCopyRequestPasses() {
   std::vector<RenderPassId> copy_requests_to_iterate(
       copy_request_passes_.begin(), copy_request_passes_.end());
   while (!copy_requests_to_iterate.empty()) {
     RenderPassId first = copy_requests_to_iterate.back();
     copy_requests_to_iterate.pop_back();
     auto it = render_pass_dependencies_.find(first);
     if (it == render_pass_dependencies_.end())
       continue;
     for (auto pass : it->second) {
       if (copy_request_passes_.insert(pass).second) {
         copy_requests_to_iterate.push_back(pass);
       }
     }
   }
 }
 
-std::unique_ptr<CompositorFrame> SurfaceAggregator::Aggregate(
-    SurfaceId surface_id) {
+CompositorFrame SurfaceAggregator::Aggregate(SurfaceId surface_id) {
   Surface* surface = manager_->GetSurfaceForId(surface_id);
   DCHECK(surface);
   contained_surfaces_[surface_id] = surface->frame_index();
-  const CompositorFrame* root_surface_frame = surface->GetEligibleFrame();
-  if (!root_surface_frame)
-    return nullptr;
+  const CompositorFrame& root_surface_frame = surface->GetEligibleFrame();
+  if (!root_surface_frame.delegated_frame_data)
+    return CompositorFrame();
   TRACE_EVENT0("cc", "SurfaceAggregator::Aggregate");
 
-  std::unique_ptr<CompositorFrame> frame(new CompositorFrame);
-  frame->delegated_frame_data = base::WrapUnique(new DelegatedFrameData);
+  CompositorFrame frame;
+  frame.delegated_frame_data = base::WrapUnique(new DelegatedFrameData);
 
-  DCHECK(root_surface_frame->delegated_frame_data);
-
-  dest_resource_list_ = &frame->delegated_frame_data->resource_list;
-  dest_pass_list_ = &frame->delegated_frame_data->render_pass_list;
+  dest_resource_list_ = &frame.delegated_frame_data->resource_list;
+  dest_pass_list_ = &frame.delegated_frame_data->render_pass_list;
 
   valid_surfaces_.clear();
   PrewalkResult prewalk_result;
   root_damage_rect_ =
       PrewalkTree(surface_id, false, RenderPassId(), &prewalk_result);
   PropagateCopyRequestPasses();
   has_copy_requests_ = !copy_request_passes_.empty();
 
   CopyUndrawnSurfaces(&prewalk_result);
   SurfaceSet::iterator it = referenced_surfaces_.insert(surface_id).first;
-  CopyPasses(root_surface_frame->delegated_frame_data.get(), surface);
+  CopyPasses(root_surface_frame.delegated_frame_data.get(), surface);
   referenced_surfaces_.erase(it);
 
   moved_pixel_passes_.clear();
   copy_request_passes_.clear();
   render_pass_dependencies_.clear();
 
   DCHECK(referenced_surfaces_.empty());
 
   if (dest_pass_list_->empty())
-    return nullptr;
+    return CompositorFrame();
 
   dest_pass_list_ = NULL;
   ProcessAddedAndRemovedSurfaces();
   contained_surfaces_.swap(previous_contained_surfaces_);
   contained_surfaces_.clear();
 
   for (SurfaceIndexMap::iterator it = previous_contained_surfaces_.begin();
        it != previous_contained_surfaces_.end();
        ++it) {
     Surface* surface = manager_->GetSurfaceForId(it->first);
     if (surface)
-      surface->TakeLatencyInfo(&frame->metadata.latency_info);
+      surface->TakeLatencyInfo(&frame.metadata.latency_info);
   }
 
   // TODO(jamesr): Aggregate all resource references into the returned frame's
   // resource list.
 
   return frame;
 }
 
 void SurfaceAggregator::ReleaseResources(SurfaceId surface_id) {
   SurfaceToResourceChildIdMap::iterator it =
       surface_id_to_resource_child_id_.find(surface_id);
   if (it != surface_id_to_resource_child_id_.end()) {
     provider_->DestroyChild(it->second);
     surface_id_to_resource_child_id_.erase(it);
   }
 }
 
 void SurfaceAggregator::SetFullDamageForSurface(SurfaceId surface_id) {
   auto it = previous_contained_surfaces_.find(surface_id);
   if (it == previous_contained_surfaces_.end())
     return;
   // Set the last drawn index as 0 to ensure full damage next time it's drawn.
   it->second = 0;
 }
 
 }  // namespace cc