Flush after ResourcePool deletions complete

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 6547109d3a5f35a9a409073f1a0bc3d6b93041c2..6b0571438877e16bc5c30b96aefd61b08fe7a38d 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -847,6 +847,11 @@ void ResourceProvider::DeleteResourceInternal(ResourceMap::iterator it,
   resources_.erase(it);
 }
 
+void ResourceProvider::FlushPendingDeletions() const {
+  if (auto* gl = ContextGL())
+    gl->ShallowFlushCHROMIUM();
+}
+
 ResourceProvider::ResourceType ResourceProvider::GetResourceType(
     ResourceId id) {
   return GetResource(id)->type;