[cc] Plumb BeginFrameAcks through SurfaceManager to DisplayScheduler.

cc/surfaces/surface_manager.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_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <queue>
@@ skipping 100 matching lines @@
   surfaces_to_destroy_.erase(it);
   surface->set_destroyed(false);
   DCHECK_EQ(compositor_frame_sink_support.get(),
             surface->compositor_frame_sink_support().get());
   return surface;
 }
 
 void SurfaceManager::DestroySurface(std::unique_ptr<Surface> surface) {
   DCHECK(thread_checker_.CalledOnValidThread());
   surface->set_destroyed(true);
+  for (auto& observer : observer_list_)

[sunnyps, 2017/05/25 20:49:13]

nit: Why OnSurfaceDestroyed in addition to OnSurfaceDiscarded? Is it because
surfaces which are destroyed but not discarded may be drawn by other surfaces
but acks will not be submitted any more? I don't know if this difference is
important in practice.

[Eric Seckler, 2017/05/26 10:57:52]

I want to avoid waiting for destroyed Surfaces (that haven't yet been gc-ed for
some reason), since they won't receive a SurfaceModified (and with that, a
BeginFrameAck) for any potentially pending BeginFrame.

I'm not sure in which situations a destroyed Surface may actually remain alive,
but making assumptions about this seems dangerous anyway (?).

Keeping as-is for now.

+    observer.OnSurfaceDestroyed(surface->surface_id());
   surfaces_to_destroy_.push_back(std::move(surface));
   GarbageCollectSurfaces();
 }
 
 void SurfaceManager::RequireSequence(const SurfaceId& surface_id,
                                      const SurfaceSequence& sequence) {
   auto* surface = GetSurfaceForId(surface_id);
   if (!surface) {
     DLOG(ERROR) << "Attempting to require callback on nonexistent surface";
     return;
@@ skipping 315 matching lines @@
 }
 
 Surface* SurfaceManager::GetSurfaceForId(const SurfaceId& surface_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   if (it == surface_map_.end())
     return nullptr;
   return it->second;
 }
 
-bool SurfaceManager::SurfaceModified(const SurfaceId& surface_id) {
+bool SurfaceManager::SurfaceModified(const SurfaceId& surface_id,
+                                     const BeginFrameAck& ack) {
   CHECK(thread_checker_.CalledOnValidThread());
   bool changed = false;
   for (auto& observer : observer_list_)
-    observer.OnSurfaceDamaged(surface_id, &changed);
+    observer.OnSurfaceDamaged(surface_id, ack, &changed);
   return changed;
 }
 
 void SurfaceManager::SurfaceCreated(const SurfaceInfo& surface_info) {
   CHECK(thread_checker_.CalledOnValidThread());
 
   if (lifetime_type_ == LifetimeType::REFERENCES) {
     // We can get into a situation where multiple CompositorFrames arrive for
     // a CompositorFrameSink before the client can add any references for the
     // frame. When the second frame with a new size arrives, the first will be
@@ skipping 22 matching lines @@
   }
 }
 
 void SurfaceManager::SurfaceDiscarded(Surface* surface) {
   for (auto& observer : observer_list_)
     observer.OnSurfaceDiscarded(surface->surface_id());
   if (dependency_tracker_)
     dependency_tracker_->OnSurfaceDiscarded(surface);
 }
 
+void SurfaceManager::SurfaceDamageExpected(const SurfaceId& surface_id,
+                                           const BeginFrameArgs& args) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  for (auto& observer : observer_list_)
+    observer.OnSurfaceDamageExpected(surface_id, args);
+}
+
 void SurfaceManager::UnregisterSurface(const SurfaceId& surface_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   SurfaceMap::iterator it = surface_map_.find(surface_id);
   DCHECK(it != surface_map_.end());
   surface_map_.erase(it);
   RemoveAllSurfaceReferences(surface_id);
 }
 
 #if DCHECK_IS_ON()
 void SurfaceManager::SurfaceReferencesToStringImpl(const SurfaceId& surface_id,
@@ skipping 32 matching lines @@
     std::vector<SurfaceId> children(iter->second.begin(), iter->second.end());
     std::sort(children.begin(), children.end());
 
     for (const SurfaceId& child_id : children)
       SurfaceReferencesToStringImpl(child_id, indent + "  ", str);
   }
 }
 #endif  // DCHECK_IS_ON()
 
 }  // namespace cc