cc: Plumbing for BeginFrameSource based on Surfaces

cc/surfaces/surface.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.h"
 
 #include <algorithm>
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_id_allocator.h"
 #include "cc/surfaces/surface_manager.h"
 
 namespace cc {
 
+namespace {
+template <typename Collection, typename Value>

[mithro-old, 2015/10/01 03:00:23]

nit: Could we get a comment about why this is here.

[brianderson, 2015/10/07 20:54:48]

No longer needed with a std::set.

+void EraseValueAndCompact(Collection* collection, const Value& value) {
+  collection->erase(std::remove(collection->begin(), collection->end(), value),
+                    collection->end());
+}
+}  // namespace
+
 // The frame index starts at 2 so that empty frames will be treated as
 // completely damaged the first time they're drawn from.
 static const int kFrameIndexStart = 2;
 
 Surface::Surface(SurfaceId id, SurfaceFactory* factory)
     : surface_id_(id),
       factory_(factory->AsWeakPtr()),
       frame_index_(kFrameIndexStart),
       destroyed_(false) {}
 
 Surface::~Surface() {
   ClearCopyRequests();
   if (current_frame_ && factory_) {
     ReturnedResourceArray current_resources;
     TransferableResource::ReturnResources(
         current_frame_->delegated_frame_data->resource_list,
         &current_resources);
     factory_->UnrefResources(current_resources);
   }
   if (!draw_callback_.is_null())
     draw_callback_.Run(SurfaceDrawStatus::DRAW_SKIPPED);
+
+  if (factory_)
+    factory_->SetBeginFrameSource(surface_id_, NULL);
 }
 
 void Surface::QueueFrame(scoped_ptr<CompositorFrame> frame,
                          const DrawCallback& callback) {
   DCHECK(factory_);
   ClearCopyRequests();
 
   if (frame) {
     TakeLatencyInfo(&frame->metadata.latency_info);
   }
@@ skipping 109 matching lines @@
   destruction_dependencies_.erase(
       std::remove_if(destruction_dependencies_.begin(),
                      destruction_dependencies_.end(),
                      [sequences, valid_id_namespaces](SurfaceSequence seq) {
                        return (!!sequences->erase(seq) ||
                                !valid_id_namespaces->count(seq.id_namespace));
                      }),
       destruction_dependencies_.end());
 }
 
+void Surface::AddBeginFrameSource(BeginFrameSource* begin_frame_source) {
+  DCHECK(base::STLIsSorted(begin_frame_sources_));
+
+  // Find the insertion point.
+  auto insert_index = begin_frame_sources_.begin();
+  while (insert_index != begin_frame_sources_.end()) {
+    if (begin_frame_source < *insert_index)
+      break;
+    insert_index++;
+  }
+
+  // Verify it doesn't already exist and insert it.
+  DCHECK(insert_index == begin_frame_sources_.end() ||
+         *insert_index != begin_frame_source);
+  begin_frame_sources_.insert(insert_index, begin_frame_source);
+  UpdatePrimaryBeginFrameSource();
+}
+
+void Surface::RemoveBeginFrameSource(BeginFrameSource* begin_frame_source) {
+  DCHECK(ContainsValue(begin_frame_sources_, begin_frame_source));
+  EraseValueAndCompact(&begin_frame_sources_, begin_frame_source);
+  UpdatePrimaryBeginFrameSource();
+}
+
+void Surface::UpdatePrimaryBeginFrameSource() {
+  // Ensure the BeginFrameSources are sorted so our we make a stable decision
+  // regarding which source is primary.
+  // TODO(brianderson): Do something smarter based on coverage instead.
+  DCHECK(base::STLIsSorted(begin_frame_sources_));
+
+  BeginFrameSource* primary_source = nullptr;
+  if (!begin_frame_sources_.empty())
+    primary_source = begin_frame_sources_[0];
+
+  if (factory_)
+    factory_->SetBeginFrameSource(surface_id_, primary_source);
+}
+
 void Surface::ClearCopyRequests() {
   if (current_frame_) {
     for (const auto& render_pass :
          current_frame_->delegated_frame_data->render_pass_list) {
       for (const auto& copy_request : render_pass->copy_requests)
         copy_request->SendEmptyResult();
     }
   }
 }
 
 }  // namespace cc