cc: Move ownership of surfaces to SurfaceManager

cc/surfaces/compositor_frame_sink_support.cc

 // Copyright 2016 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/compositor_frame_sink_support.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "cc/output/compositor_frame.h"
@@ skipping 61 matching lines @@
     begin_frame_source_->RemoveObserver(this);
     added_frame_observer_ = false;
   }
   begin_frame_source_ = begin_frame_source;
   UpdateNeedsBeginFramesInternal();
 }
 
 void CompositorFrameSinkSupport::EvictCurrentSurface() {
   if (!current_surface_)
     return;
-  DestroyCurrentSurface();
+  base::WeakPtr<Surface> tmp = std::move(current_surface_);
+  surface_manager_->DestroySurface(tmp.get());
 }
 
 void CompositorFrameSinkSupport::SetNeedsBeginFrame(bool needs_begin_frame) {
   needs_begin_frame_ = needs_begin_frame;
   UpdateNeedsBeginFramesInternal();
 }
 
 void CompositorFrameSinkSupport::DidNotProduceFrame(const BeginFrameAck& ack) {
   TRACE_EVENT2("cc", "CompositorFrameSinkSupport::DidNotProduceFrame",
                "ack.source_id", ack.source_id, "ack.sequence_number",
@@ skipping 27 matching lines @@
                                "RenderWidgetHostImpl::OnSwapCompositorFrame")) {
     std::vector<ui::LatencyInfo>().swap(frame.metadata.latency_info);
   }
   for (ui::LatencyInfo& latency : frame.metadata.latency_info) {
     if (latency.latency_components().size() > 0) {
       latency.AddLatencyNumber(ui::DISPLAY_COMPOSITOR_RECEIVED_FRAME_COMPONENT,
                                0, 0);
     }
   }
 
-  std::unique_ptr<Surface> surface;
-  bool create_new_surface =
-      (!current_surface_ ||
-       local_surface_id != current_surface_->surface_id().local_surface_id());
-  if (!create_new_surface) {
-    surface = std::move(current_surface_);
-  } else {
+  Surface* prev_surface = current_surface_.get();

[kylechar, 2017/06/16 19:13:30]

This is the only place you really use the Surface*. Can you hold onto a
SurfaceId and look it up here? That would eliminate all of the added WeakPtr
code.

[Saman Sami, 2017/06/19 22:16:46]

Done.

+  if (!current_surface_ ||
+      local_surface_id != current_surface_->surface_id().local_surface_id()) {
     SurfaceId surface_id(frame_sink_id_, local_surface_id);
     gfx::Size frame_size = frame.render_pass_list.back()->output_rect.size();
     float device_scale_factor = frame.metadata.device_scale_factor;
     SurfaceInfo surface_info(surface_id, device_scale_factor, frame_size);
 
     if (!surface_info.is_valid()) {
       TRACE_EVENT_INSTANT0("cc", "Invalid SurfaceInfo",
                            TRACE_EVENT_SCOPE_THREAD);
       if (current_surface_)
-        DestroyCurrentSurface();
+        EvictCurrentSurface();
       ReturnedResourceArray resources;
       TransferableResource::ReturnResources(frame.resource_list, &resources);
       ReturnResources(resources);
       DidReceiveCompositorFrameAck();
       return true;
     }
 
-    surface = CreateSurface(surface_info);
+    current_surface_ = CreateSurface(surface_info);
   }
 
-  bool result = surface->QueueFrame(
+  bool result = current_surface_->QueueFrame(
       std::move(frame),
       base::Bind(&CompositorFrameSinkSupport::DidReceiveCompositorFrameAck,
                  weak_factory_.GetWeakPtr()),
       base::BindRepeating(&CompositorFrameSinkSupport::WillDrawSurface,
                           weak_factory_.GetWeakPtr()));
 
   if (!result) {
-    surface_manager_->DestroySurface(std::move(surface));
+    EvictCurrentSurface();
     return false;
   }
 
-  if (current_surface_) {
-    surface->SetPreviousFrameSurface(current_surface_.get());
-    DestroyCurrentSurface();
+  if (prev_surface && prev_surface != current_surface_.get()) {
+    current_surface_->SetPreviousFrameSurface(prev_surface);
+    surface_manager_->DestroySurface(prev_surface);
   }
-  current_surface_ = std::move(surface);
 
   if (begin_frame_source_)
     begin_frame_source_->DidFinishFrame(this);
 
   return true;
 }
 
 void CompositorFrameSinkSupport::UpdateSurfaceReferences(
     const LocalSurfaceId& local_surface_id,
     const std::vector<SurfaceId>& active_referenced_surfaces) {
@@ skipping 149 matching lines @@
   if (needs_begin_frame_ == added_frame_observer_)
     return;
 
   added_frame_observer_ = needs_begin_frame_;
   if (needs_begin_frame_)
     begin_frame_source_->AddObserver(this);
   else
     begin_frame_source_->RemoveObserver(this);
 }
 
-std::unique_ptr<Surface> CompositorFrameSinkSupport::CreateSurface(
+base::WeakPtr<Surface> CompositorFrameSinkSupport::CreateSurface(
     const SurfaceInfo& surface_info) {
   seen_first_frame_activation_ = false;
   return surface_manager_->CreateSurface(weak_factory_.GetWeakPtr(),
                                          surface_info);
 }
 
-void CompositorFrameSinkSupport::DestroyCurrentSurface() {
-  surface_manager_->DestroySurface(std::move(current_surface_));
-}
-
 void CompositorFrameSinkSupport::RequestCopyOfSurface(
     std::unique_ptr<CopyOutputRequest> copy_request) {
   if (!current_surface_)
     return;
 
   DCHECK(current_surface_->compositor_frame_sink_support().get() == this);
   current_surface_->RequestCopyOfOutput(std::move(copy_request));
   BeginFrameAck ack;
   ack.has_damage = true;
   if (current_surface_->HasActiveFrame())
     surface_manager_->SurfaceModified(current_surface_->surface_id(), ack);
 }
 
 }  // namespace cc