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

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

 // 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.
 
 #include "services/resource_coordinator/public/cpp/memory/memory_dump_manager_delegate_impl.h"
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/single_thread_task_runner.h"
+#include "base/synchronization/lock.h"
 #include "base/trace_event/memory_dump_request_args.h"
 #include "mojo/public/cpp/bindings/interface_request.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 {
 
+MemoryDumpManagerDelegateImpl::Config::~Config() {}
+
 MemoryDumpManagerDelegateImpl::MemoryDumpManagerDelegateImpl(
-    service_manager::InterfaceProvider* interface_provider)
-    : is_coordinator_(false), binding_(this) {
-  interface_provider->GetInterface(mojo::MakeRequest(&coordinator_));
+    const MemoryDumpManagerDelegateImpl::Config& config)
+    : binding_(this),
+      config_(config),
+      task_runner_(nullptr),
+      pending_memory_dump_guid_(0) {
+  if (config.interface_provider() != nullptr) {
+    config.interface_provider()->GetInterface(mojo::MakeRequest(&coordinator_));
+  } else {
+    task_runner_ = base::ThreadTaskRunnerHandle::Get();
+    config.coordinator()->BindCoordinatorRequest(
+        mojo::MakeRequest(&coordinator_));
+  }
   coordinator_->RegisterProcessLocalDumpManager(
       binding_.CreateInterfacePtrAndBind());
 }
-
-MemoryDumpManagerDelegateImpl::MemoryDumpManagerDelegateImpl(
-    Coordinator* coordinator)
-    : is_coordinator_(true), binding_(this) {
-  coordinator->BindCoordinatorRequest(mojo::MakeRequest(&coordinator_));
-  coordinator_->RegisterProcessLocalDumpManager(
-      binding_.CreateInterfacePtrAndBind());
-}
 
 MemoryDumpManagerDelegateImpl::~MemoryDumpManagerDelegateImpl() {}
 
 bool MemoryDumpManagerDelegateImpl::IsCoordinator() const {
-  return is_coordinator_;
+  return task_runner_ != nullptr;
 }
 
 void MemoryDumpManagerDelegateImpl::RequestProcessMemoryDump(
     const base::trace_event::MemoryDumpRequestArgs& args,
     const RequestProcessMemoryDumpCallback& callback) {
   MemoryDumpManagerDelegate::CreateProcessDump(args, callback);
 }
 
 void MemoryDumpManagerDelegateImpl::RequestGlobalMemoryDump(
     const base::trace_event::MemoryDumpRequestArgs& args,
     const base::trace_event::MemoryDumpCallback& callback) {
-  coordinator_->RequestGlobalMemoryDump(args, callback);
+  // Note: This condition is here to match the old behavior. If the delegate is
+  // in the browser process, we do not drop parallel requests in the delegate
+  // and so they will be queued by the Coordinator service (see
+  // CoordinatorImpl::RequestGlobalMemoryDump). If the delegate is in a child
+  // process, parallel requests will be cancelled.
+  //
+  // TODO(chiniforooshan): Unify the child and browser behavior.
+  if (IsCoordinator()) {
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&mojom::Coordinator::RequestGlobalMemoryDump,
+                   base::Unretained(coordinator_.get()), args, callback));
+    return;
+  }
+
+  {
+    base::AutoLock lock(pending_memory_dump_guid_lock_);
+    if (pending_memory_dump_guid_) {
+      callback.Run(args.dump_guid, false);
+      return;
+    }
+    pending_memory_dump_guid_ = args.dump_guid;
+  }
+  auto callback_proxy =
+      base::Bind(&MemoryDumpManagerDelegateImpl::MemoryDumpCallbackProxy,
+                 base::Unretained(this), callback);
+  coordinator_->RequestGlobalMemoryDump(args, callback_proxy);
+}
+
+void MemoryDumpManagerDelegateImpl::MemoryDumpCallbackProxy(
+    const base::trace_event::MemoryDumpCallback& callback,
+    uint64_t dump_guid,
+    bool success) {
+  DCHECK_NE(0U, pending_memory_dump_guid_);
+  pending_memory_dump_guid_ = 0;
+  callback.Run(dump_guid, success);
+}
+
+void MemoryDumpManagerDelegateImpl::SetAsNonCoordinatorForTesting() {
+  task_runner_ = nullptr;
 }
 
 }  // namespace memory_instrumentation