Add MemoryCoordinatorDelegate

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/browser/render_process_host.h"
 #include "content/public/common/content_features.h"
 
 namespace content {
 
+// static
+void MemoryCoordinatorDelegate::Set(
+    const base::WeakPtr<MemoryCoordinatorDelegate>& delegate) {
+  auto* coordinator = MemoryCoordinator::GetInstance();
+  if (coordinator)
+    coordinator->SetDelegate(delegate);
+}
+
 // The implementation of MemoryCoordinatorHandle. See memory_coordinator.mojom
 // for the role of this class.
 class MemoryCoordinatorHandleImpl : public mojom::MemoryCoordinatorHandle {
  public:
   MemoryCoordinatorHandleImpl(mojom::MemoryCoordinatorHandleRequest request)
       : binding_(this, std::move(request)) {
   }
 
   // mojom::MemoryCoordinatorHandle:
   void AddChild(mojom::ChildMemoryCoordinatorPtr child) override {
@@ skipping 46 matching lines @@
 
   // Can't send a message to a child that doesn't exist.
   auto iter = children_.find(render_process_id);
   if (iter == children_.end())
     return false;
 
   // A nop doesn't need to be sent, but is considered successful.
   if (iter->second.memory_state == memory_state)
     return true;
 
+  // Can't suspend the given renderer.
+  if (memory_state == mojom::MemoryState::SUSPENDED &&
+      !CanSuspendRenderer(render_process_id))
+    return false;
+
   // Update the internal state and send the message.
   iter->second.memory_state = memory_state;
   iter->second.handle->child()->OnStateChange(memory_state);
   return true;
 }
 
 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;
 }
 
 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));
 }
 
 void MemoryCoordinator::OnConnectionError(int render_process_id) {
   children_.erase(render_process_id);
 }
 
+bool MemoryCoordinator::CanSuspendRenderer(int render_process_id) {
+  // If there is no delegate (i.e. tests), renderers are always suspendable.
+  if (!delegate_)
+    return true;
+  auto* render_process_host = RenderProcessHost::FromID(render_process_id);
+  if (!render_process_host->IsProcessBackgrounded())
+      return false;
+  return delegate_->CanSuspendBackgroundedRenderer(render_process_id);
+}
+
 void MemoryCoordinator::CreateChildInfoMapEntry(
     int render_process_id,
     std::unique_ptr<MemoryCoordinatorHandleImpl> handle) {
   auto& child_info = children_[render_process_id];
   // Process always start with normal memory state.
   // TODO(chrisha): Consider having memory state be a startup parameter of
   // child processes, allowing them to be launched in a restricted state.
   child_info.memory_state = mojom::MemoryState::NORMAL;
   child_info.handle = std::move(handle);
 }
 
 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