Add ChildMemoryCoordinator::PurgeMemory()

content/child/memory/child_memory_coordinator_impl.cc

Index: content/child/memory/child_memory_coordinator_impl.cc
diff --git a/content/child/memory/child_memory_coordinator_impl.cc b/content/child/memory/child_memory_coordinator_impl.cc
index e961c6bcdd2b120b6e3dff01e30b9895d6fa6dbb..037780985f74e275a9ef31ecfda7802b68fd5c0c 100644
--- a/content/child/memory/child_memory_coordinator_impl.cc
+++ b/content/child/memory/child_memory_coordinator_impl.cc
@@ -58,6 +58,14 @@ ChildMemoryCoordinatorImpl::~ChildMemoryCoordinatorImpl() {
   g_child_memory_coordinator = nullptr;
 }
 
+void ChildMemoryCoordinatorImpl::PurgeMemory() {
+  base::MemoryCoordinatorClientRegistry::GetInstance()->PurgeMemory();
+  // TODO(bashi): Remove following notification when all clients implement
+  // OnPurgeMemory();
+  base::MemoryCoordinatorClientRegistry::GetInstance()->Notify(
+      base::MemoryState::SUSPENDED);
+}
+
 void ChildMemoryCoordinatorImpl::OnStateChange(mojom::MemoryState state) {
   base::MemoryState base_state = ToBaseMemoryState(state);
   TRACE_EVENT1("memory-infra", "ChildMemoryCoordinatorImpl::OnStateChange",