Introduce MemoryCoordinatorProxy in base

content/browser/memory/memory_coordinator.cc

Index: content/browser/memory/memory_coordinator.cc
diff --git a/content/browser/memory/memory_coordinator.cc b/content/browser/memory/memory_coordinator.cc
index ed6dde02a12660b4349c0a5b59735eaa5cd237f5..0d292ee6cbaba37d4742cbcab3efff3143f75955 100644
--- a/content/browser/memory/memory_coordinator.cc
+++ b/content/browser/memory/memory_coordinator.cc
@@ -120,6 +120,14 @@ mojom::MemoryState MemoryCoordinator::GetMemoryState(
   return iter->second.memory_state;
 }
 
+void MemoryCoordinator::EnableFeaturesForTesting() {
+  base::FeatureList::ClearInstanceForTesting();
+  std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->InitializeFromCommandLine(features::kMemoryCoordinator.name,
+                                          "");
+  base::FeatureList::SetInstance(std::move(feature_list));
+}
+
 base::MemoryState MemoryCoordinator::GetCurrentMemoryState() const {
   return base::MemoryState::UNKNOWN;
 }