viz: Remove SurfaceManager::GetValidFrameSinkIds

The set of valid FrameSinkIds is a concept used for SurfaceSequences
which are deprecated. We cannot remove SurfaceSequence code just yet
but GetValidFrameSinkIds is a publicly exposed method that is used
by FrameSinkManager for some DCHECKs. These DCHECKs are not really
necessary and removing them allows us to delete a public method
in SurfaceManager, simplifying its interface.

Bug: 722935
TBR: piman@chromium.org
Change-Id: I220a591d26e5bcd366eaa9a24404179f7439f49c
Reviewed-on: https://chromium-review.googlesource.com/574575
Commit-Queue: Fady Samuel <fsamuel@chromium.org>
Reviewed-by: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487149}

cc/surfaces/surface_manager.h

@@ -183,10 +183,6 @@ class CC_SURFACES_EXPORT SurfaceManager {
     return lifetime_type_ == LifetimeType::REFERENCES;
   }
 
-  const base::flat_set<viz::FrameSinkId>& GetValidFrameSinkIds() {
-    return valid_frame_sink_ids_;
-  }
-
  private:
   friend class test::SurfaceSynchronizationTest;
   friend class SurfaceManagerRefTest;

components/viz/service/frame_sinks/frame_sink_manager.cc

@@ -46,7 +46,6 @@ void FrameSinkManager::RegisterFrameSinkManagerClient(
     const FrameSinkId& frame_sink_id,
     FrameSinkManagerClient* client) {
   DCHECK(client);
-  DCHECK_EQ(surface_manager_.GetValidFrameSinkIds().count(frame_sink_id), 1u);
 
   clients_[frame_sink_id] = client;
 
@@ -59,7 +58,6 @@ void FrameSinkManager::RegisterFrameSinkManagerClient(
 
 void FrameSinkManager::UnregisterFrameSinkManagerClient(
     const FrameSinkId& frame_sink_id) {
-  DCHECK_EQ(surface_manager_.GetValidFrameSinkIds().count(frame_sink_id), 1u);
   auto client_iter = clients_.find(frame_sink_id);
   DCHECK(client_iter != clients_.end());
 
@@ -76,7 +74,6 @@ void FrameSinkManager::RegisterBeginFrameSource(
     const FrameSinkId& frame_sink_id) {
   DCHECK(source);
   DCHECK_EQ(registered_sources_.count(source), 0u);
-  DCHECK_EQ(surface_manager_.GetValidFrameSinkIds().count(frame_sink_id), 1u);
 
   registered_sources_[source] = frame_sink_id;
   RecursivelyAttachBeginFrameSource(frame_sink_id, source);