Add OnPurgeMemory() to MemoryCoordinatorClient

base/memory/memory_coordinator_client_registry.cc

Index: base/memory/memory_coordinator_client_registry.cc
diff --git a/base/memory/memory_coordinator_client_registry.cc b/base/memory/memory_coordinator_client_registry.cc
index 57eedc683c38cc31107fb530b86cc5a62826b037..67064581ab001efceb06e3ef51f77fe7fc250830 100644
--- a/base/memory/memory_coordinator_client_registry.cc
+++ b/base/memory/memory_coordinator_client_registry.cc
@@ -34,4 +34,8 @@ void MemoryCoordinatorClientRegistry::Notify(MemoryState state) {
                    &base::MemoryCoordinatorClient::OnMemoryStateChange, state);
 }
 
+void MemoryCoordinatorClientRegistry::PurgeMemory() {
+  clients_->Notify(FROM_HERE, &base::MemoryCoordinatorClient::OnPurgeMemory);
+}
+
 }  // namespace base