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 d052ab0e10888e978fd7690cfacd013ab4cd5fa5..7724519a16a8224a3d8097490515ee52d25c1a29 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(TRACE_DISABLED_BY_DEFAULT("memory-infra"),