Surfaces: Allow parent to refer to child surfaces that don't exist yet.

cc/surfaces/surface_manager_ref_unittest.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 <stddef.h>
 
 #include <unordered_map>
 #include <vector>
 
 #include "base/memory/ptr_util.h"
@@ skipping 248 matching lines @@
 
   RemoveSurfaceReference(manager().GetRootSurfaceId(), id1);
 
   // Removing the reference from the root to id1 should allow all three surfaces
   // to be deleted during GC.
   EXPECT_EQ(nullptr, manager().GetSurfaceForId(id1));
   EXPECT_EQ(nullptr, manager().GetSurfaceForId(id2));
   EXPECT_EQ(nullptr, manager().GetSurfaceForId(id3));
 }
 
-TEST_F(SurfaceManagerRefTest, TryAddReferenceToBadSurface) {
-  // Not creating an accompanying Surface and SurfaceFactory.
-  SurfaceId id(FrameSinkId(100u, 200u),
-               LocalSurfaceId(1u, base::UnguessableToken::Create()));
-
-  // Adding reference from root to the Surface should do nothing because
-  // SurfaceManager doesn't know Surface for |id| exists.
-  manager().AddSurfaceReference(manager().GetRootSurfaceId(), id);
-  EXPECT_THAT(GetReferencesFor(id), IsEmpty());
-}
-
 TEST_F(SurfaceManagerRefTest, TryDoubleAddReference) {
   SurfaceId id1 = CreateSurface(kFrameSink1, 1);
   SurfaceId id2 = CreateSurface(kFrameSink2, 1);
 
   manager().AddSurfaceReference(manager().GetRootSurfaceId(), id1);
   manager().AddSurfaceReference(id1, id2);
   EXPECT_THAT(GetReferencesFor(id2), SizeIs(1));
   EXPECT_THAT(GetReferencesFrom(id1), SizeIs(1));
 
   // The second request should be ignored without crashing.
@@ skipping 143 matching lines @@
   // reference should be removed. The temporary reference for |surface_id2|
   // should remain. A temporary reference must be added for |parent_id|.
   EXPECT_THAT(GetAllTempReferences(),
               UnorderedElementsAre(parent_id, surface_id2));
   EXPECT_THAT(GetReferencesFromRoot(),
               UnorderedElementsAre(parent_id, surface_id2));
   EXPECT_THAT(GetReferencesFrom(parent_id), ElementsAre(surface_id1));
 }
 
 }  // namespace cc