Add MemoryCoordinatorDelegate

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 52ee2ece71f8a47def79edd5401bd9c791680b49..45a6375732aa0cf801b49fcdffb37777d71cb6ff 100644
--- a/content/browser/memory/memory_coordinator.cc
+++ b/content/browser/memory/memory_coordinator.cc
@@ -5,10 +5,19 @@
 #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 {
@@ -75,6 +84,11 @@ bool MemoryCoordinator::SetMemoryState(int render_process_id,
   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);
@@ -103,6 +117,16 @@ 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) {