memory-infra: Finish moving to Mojo (3nd attempt)

services/resource_coordinator/public/cpp/memory/memory_dump_manager_delegate_impl.h

 // Copyright 2017 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.
 
 #ifndef SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_MEMORY_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_
 #define SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_MEMORY_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_
 
+#include "base/single_thread_task_runner.h"
+#include "base/synchronization/lock.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "base/trace_event/memory_dump_request_args.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/resource_coordinator/public/cpp/memory/coordinator.h"
 #include "services/resource_coordinator/public/interfaces/memory/memory_instrumentation.mojom.h"
 #include "services/service_manager/public/cpp/interface_provider.h"
 
 namespace memory_instrumentation {
 
+// This is the bridge between MemoryDumpManager and the Coordinator service.
+// This indirection is needed to avoid a dependency from //base, where
+// MemoryDumpManager lives, to //services, where the Coordinator service lives.
+//
+// This cannot just be implemented by the Coordinator service, because there is
+// no Coordinator service in child processes. So, in a child process, the
+// delegate remotely connects to the Coordinator service. In the browser
+// process, the delegate locally connects to the Coordinator service.
 class MemoryDumpManagerDelegateImpl
     : public base::trace_event::MemoryDumpManagerDelegate,
       public mojom::ProcessLocalDumpManager {
  public:
-  // Use to bind to a remote coordinator.
-  MemoryDumpManagerDelegateImpl(
-      service_manager::InterfaceProvider* interface_provider);
+  class Config {
+   public:
+    Config(service_manager::InterfaceProvider* interface_provider)
+        : interface_provider_(interface_provider), coordinator_(nullptr) {}
+    Config(Coordinator* coordinator)
+        : interface_provider_(nullptr), coordinator_(coordinator) {}
+    ~Config();
 
-  // Use to bind to a coordinator in the same process.
-  MemoryDumpManagerDelegateImpl(Coordinator* coordinator);
+    service_manager::InterfaceProvider* interface_provider() const {
+      return interface_provider_;
+    }
+
+    Coordinator* coordinator() const { return coordinator_; }
+
+   private:
+    service_manager::InterfaceProvider* interface_provider_;
+    Coordinator* coordinator_;
+    bool is_test_config_;
+  };
+
+  explicit MemoryDumpManagerDelegateImpl(const Config& config);
   ~MemoryDumpManagerDelegateImpl() override;
 
-  bool IsCoordinator() const;
+  bool IsCoordinator() const override;
 
   // The base::trace_event::MemoryDumpManager calls this.
   void RequestGlobalMemoryDump(
       const base::trace_event::MemoryDumpRequestArgs& args,
       const base::trace_event::MemoryDumpCallback& callback) override;
 
+  Config config() { return config_; }
+  void SetAsNonCoordinatorForTesting();
+
  private:
+  friend std::default_delete<MemoryDumpManagerDelegateImpl>;  // For testing
+  friend class MemoryDumpManagerDelegateImplTest;             // For testing
+
   // The ProcessLocalDumpManager interface. The coordinator calls this.
   void RequestProcessMemoryDump(
       const base::trace_event::MemoryDumpRequestArgs& args,
       const RequestProcessMemoryDumpCallback& callback) override;
 
-  bool is_coordinator_;
+  // A proxy callback for updating |pending_memory_dump_guid_|.
+  void MemoryDumpCallbackProxy(
+      const base::trace_event::MemoryDumpCallback& callback,
+      uint64_t dump_guid,
+      bool success);
+
   mojom::CoordinatorPtr coordinator_;
   mojo::Binding<mojom::ProcessLocalDumpManager> binding_;
+  const Config config_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  uint64_t pending_memory_dump_guid_;
+
+  // Prevents racy access to |pending_memory_dump_guid_|.
+  base::Lock pending_memory_dump_guid_lock_;
+
+  // Prevents racy access to |initialized_|.
+  base::Lock initialized_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(MemoryDumpManagerDelegateImpl);
 };
 
 }  // namespace memory_instrumentation
 
 #endif  // SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_MEMORY_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_