Mac: Suppress asserts about resources being in use

cc/resources/resource_provider.cc

 // Copyright 2012 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/resources/resource_provider.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 769 matching lines @@
       ChildMap::iterator child_it = children_.find(resource->child_id);
       ResourceIdArray unused;
       unused.push_back(id);
       DeleteAndReturnUnusedResourcesToChild(child_it, NORMAL, unused);
     }
   }
 }
 
 ResourceProvider::Resource* ResourceProvider::LockForWrite(ResourceId id) {
   Resource* resource = GetResource(id);
-  DCHECK(CanLockForWrite(id));
-
+  // TODO(ccameron): The allowance for IsInUseByMacOSWindowServer should not
+  // be needed.
+  // http://crbug.com/577121
+  DCHECK(CanLockForWrite(id) || IsInUseByMacOSWindowServer(id));
   resource->locked_for_write = true;
   return resource;
 }
 
 bool ResourceProvider::CanLockForWrite(ResourceId id) {
   Resource* resource = GetResource(id);
   return !resource->locked_for_write && !resource->lock_for_read_count &&
          !resource->exported_count && resource->origin == Resource::INTERNAL &&
          !resource->lost && ReadLockFenceHasPassed(resource) &&
          !(resource->gpu_memory_buffer &&
            resource->gpu_memory_buffer->IsInUseByMacOSWindowServer());
 }
 
 bool ResourceProvider::IsOverlayCandidate(ResourceId id) {
   Resource* resource = GetResource(id);
   return resource->is_overlay_candidate;
 }
 
+bool ResourceProvider::IsInUseByMacOSWindowServer(ResourceId id) {
+  Resource* resource = GetResource(id);
+  return resource->gpu_memory_buffer &&
+         resource->gpu_memory_buffer->IsInUseByMacOSWindowServer();
+}
+
 void ResourceProvider::UnlockForWrite(ResourceProvider::Resource* resource) {
   DCHECK(resource->locked_for_write);
   DCHECK_EQ(resource->exported_count, 0);
   DCHECK(resource->origin == Resource::INTERNAL);
   resource->locked_for_write = false;
 }
 
 void ResourceProvider::EnableReadLockFencesForTesting(ResourceId id) {
   Resource* resource = GetResource(id);
   DCHECK(resource);
@@ skipping 960 matching lines @@
 
     const int kImportance = 2;
     pmd->CreateSharedGlobalAllocatorDump(guid);
     pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
   }
 
   return true;
 }
 
 }  // namespace cc