RC: Assume that service is created in renderer-side FrameResourceCoordinator.

mojo::MakeRequest never fails to create to initialize the InterfacePtr
and it is ok to start using the InterfacePtr before initialization is
complete.
https://cs.chromium.org/chromium/src/mojo/public/cpp/bindings/interface_request.h?l=96-99&rcl=2985a2476a50ee04dbd78b6a0c3228c5f96a2559

Change-Id: Ie5ec84cdcf8896cf646a58aca4ceab8db82eb428
Reviewed-on: https://chromium-review.googlesource.com/1249811Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595212}

third_party/blink/renderer/core/frame/local_frame.cc

@@ -1214,8 +1214,8 @@ FrameResourceCoordinator* LocalFrame::GetFrameResourceCoordinator() {
     auto* local_frame_client = Client();
     if (!local_frame_client)
       return nullptr;
-    frame_resource_coordinator_.reset(FrameResourceCoordinator::Create(
-        local_frame_client->GetInterfaceProvider()));
+    frame_resource_coordinator_ = FrameResourceCoordinator::Create(
+        local_frame_client->GetInterfaceProvider());
   }
   return frame_resource_coordinator_.get();
 }

third_party/blink/renderer/platform/instrumentation/resource_coordinator/frame_resource_coordinator.cc

@@ -4,39 +4,35 @@
 
 #include "third_party/blink/renderer/platform/instrumentation/resource_coordinator/frame_resource_coordinator.h"
 
+#include "base/memory/ptr_util.h"
 #include "services/service_manager/public/cpp/interface_provider.h"
 
 namespace blink {
 
 // static
-FrameResourceCoordinator* FrameResourceCoordinator::Create(
+std::unique_ptr<FrameResourceCoordinator> FrameResourceCoordinator::Create(
     service_manager::InterfaceProvider* interface_provider) {
-  return new FrameResourceCoordinator(interface_provider);
+  return base::WrapUnique(new FrameResourceCoordinator(interface_provider));
 }
 
 FrameResourceCoordinator::FrameResourceCoordinator(
     service_manager::InterfaceProvider* interface_provider) {
   interface_provider->GetInterface(mojo::MakeRequest(&service_));
+  DCHECK(service_);
 }
 
 FrameResourceCoordinator::~FrameResourceCoordinator() = default;
 
 void FrameResourceCoordinator::SetNetworkAlmostIdle(bool idle) {
-  if (!service_)
-    return;
   service_->SetNetworkAlmostIdle(idle);
 }
 
 void FrameResourceCoordinator::SetLifecycleState(
     resource_coordinator::mojom::LifecycleState state) {
-  if (!service_)
-    return;
   service_->SetLifecycleState(state);
 }
 
 void FrameResourceCoordinator::OnNonPersistentNotificationCreated() {
-  if (!service_)
-    return;
   service_->OnNonPersistentNotificationCreated();
 }
 

third_party/blink/renderer/platform/instrumentation/resource_coordinator/frame_resource_coordinator.h

@@ -19,7 +19,8 @@ class PLATFORM_EXPORT FrameResourceCoordinator final
   WTF_MAKE_NONCOPYABLE(FrameResourceCoordinator);
 
  public:
-  static FrameResourceCoordinator* Create(service_manager::InterfaceProvider*);
+  static std::unique_ptr<FrameResourceCoordinator> Create(
+      service_manager::InterfaceProvider*);
   ~FrameResourceCoordinator();
 
   void SetNetworkAlmostIdle(bool);