[NotForReview] An idea for experimenting purge & suspend

content/browser/memory/memory_coordinator.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/memory/memory_coordinator.h"
 
 #include "base/memory/memory_coordinator_client_registry.h"
 #include "content/public/common/content_features.h"
 
 namespace content {
@@ skipping 16 matching lines @@
   mojo::Binding<mojom::MemoryCoordinatorHandle>& binding() { return binding_; }
 
  private:
   mojom::ChildMemoryCoordinatorPtr child_;
   mojo::Binding<mojom::MemoryCoordinatorHandle> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryCoordinatorHandleImpl);
 };
 
 // static
+bool MemoryCoordinator::IsEnabled() {
+  // TODO(tasak): Remove |kPurgeAndSuspend| when the experiment is done.
+  return base::FeatureList::IsEnabled(features::kMemoryCoordinator) ||
+         base::FeatureList::IsEnabled(features::kPurgeAndSuspend);
+}
+
+// static
 MemoryCoordinator* MemoryCoordinator::GetInstance() {
-  if (!base::FeatureList::IsEnabled(features::kMemoryCoordinator))
-    return nullptr;
-  return base::Singleton<MemoryCoordinator,
-                         base::LeakySingletonTraits<MemoryCoordinator>>::get();
+  if (IsEnabled()) {
+    return base::Singleton<MemoryCoordinator, base::LeakySingletonTraits<
+                                                  MemoryCoordinator>>::get();
+  }
+  return nullptr;
 }
 
 MemoryCoordinator::MemoryCoordinator() {}
 
 MemoryCoordinator::~MemoryCoordinator() {}
 
 void MemoryCoordinator::CreateHandle(
     int render_process_id,
     mojom::MemoryCoordinatorHandleRequest request) {
   std::unique_ptr<MemoryCoordinatorHandleImpl> handle(
@@ skipping 30 matching lines @@
 }
 
 mojom::MemoryState MemoryCoordinator::GetMemoryState(
     int render_process_id) const {
   auto iter = children_.find(render_process_id);
   if (iter == children_.end())
     return mojom::MemoryState::UNKNOWN;
   return iter->second.memory_state;
 }
 
+bool MemoryCoordinator::PurgeAndSuspendChild(int render_process_id) {
+  DCHECK(base::FeatureList::IsEnabled(features::kPurgeAndSuspend));
+  return SetMemoryState(render_process_id, mojom::MemoryState::SUSPENDED);
+}
+
 void MemoryCoordinator::AddChildForTesting(
     int dummy_render_process_id, mojom::ChildMemoryCoordinatorPtr child) {
   mojom::MemoryCoordinatorHandlePtr mch;
   auto request = mojo::GetProxy(&mch);
   std::unique_ptr<MemoryCoordinatorHandleImpl> handle(
       new MemoryCoordinatorHandleImpl(std::move(request)));
   handle->AddChild(std::move(child));
   CreateChildInfoMapEntry(dummy_render_process_id, std::move(handle));
 }
 
@@ skipping 14 matching lines @@
 
 MemoryCoordinator::ChildInfo::ChildInfo() {}
 
 MemoryCoordinator::ChildInfo::ChildInfo(const ChildInfo& rhs) {
   // This is a nop, but exists for compatibility with STL containers.
 }
 
 MemoryCoordinator::ChildInfo::~ChildInfo() {}
 
 }  // namespace content