Move dedicated worker MojoUkmRecorder creation to worker thread

Bug: 881144
Change-Id: Idc5292cecf9a3d4dbc101a9c44c47bd3db62dab6
Reviewed-on: https://chromium-review.googlesource.com/1208941Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590088}

mojo/public/cpp/bindings/lib/connector.cc

@@ -392,6 +392,7 @@ void Connector::WaitToReadMore() {
   CHECK(!paused_);
   DCHECK(!handle_watcher_);
 
+  DCHECK(task_runner_->RunsTasksInCurrentSequence());
   handle_watcher_.reset(new SimpleWatcher(
       FROM_HERE, SimpleWatcher::ArmingPolicy::MANUAL, task_runner_));
   handle_watcher_->set_heap_profiler_tag(heap_profiler_tag_);

mojo/public/cpp/bindings/lib/interface_ptr_state.cc

@@ -80,6 +80,7 @@ bool InterfacePtrStateBase::InitializeEndpointClient(
           : (has_sync_methods
                  ? MultiplexRouter::SINGLE_INTERFACE_WITH_SYNC_METHODS
                  : MultiplexRouter::SINGLE_INTERFACE);
+  DCHECK(runner_->RunsTasksInCurrentSequence());
   router_ = new MultiplexRouter(std::move(handle_), config, true, runner_);
   endpoint_client_.reset(new InterfaceEndpointClient(
       router_->CreateLocalEndpointHandle(kMasterInterfaceId), nullptr,

third_party/blink/renderer/platform/scheduler/worker/worker_scheduler_proxy.cc

@@ -4,7 +4,6 @@
 
 #include "third_party/blink/renderer/platform/scheduler/worker/worker_scheduler_proxy.h"
 
-#include "services/metrics/public/cpp/mojo_ukm_recorder.h"
 #include "third_party/blink/public/platform/platform.h"
 #include "third_party/blink/renderer/platform/scheduler/main_thread/frame_scheduler_impl.h"
 #include "third_party/blink/renderer/platform/scheduler/public/worker_scheduler.h"
@@ -22,8 +21,10 @@ WorkerSchedulerProxy::WorkerSchedulerProxy(FrameOrWorkerScheduler* scheduler) {
     initial_frame_status_ = GetFrameStatus(frame_scheduler);
     ukm_source_id_ = frame_scheduler->GetUkmSourceId();
     if (ukm_source_id_ != ukm::kInvalidSourceId) {
-      ukm_recorder_ =
-          ukm::MojoUkmRecorder::Create(Platform::Current()->GetConnector());
+      // The connector must be cloned because it belongs to the main thread,
+      // but we intend to acquire and use it from the worker thread. (It must
+      // be cloned on the original owning thread, not the destination thread.)
+      connector_ = Platform::Current()->GetConnector()->Clone();
     }
   }
 }

third_party/blink/renderer/platform/scheduler/worker/worker_scheduler_proxy.h

@@ -11,8 +11,8 @@
 #include "base/optional.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_checker.h"
-#include "services/metrics/public/cpp/ukm_recorder.h"
 #include "services/metrics/public/cpp/ukm_source_id.h"
+#include "services/service_manager/public/cpp/connector.h"
 #include "third_party/blink/renderer/platform/platform_export.h"
 #include "third_party/blink/renderer/platform/scheduler/main_thread/frame_origin_type.h"
 #include "third_party/blink/renderer/platform/scheduler/public/frame_or_worker_scheduler.h"
@@ -62,13 +62,13 @@ class PLATFORM_EXPORT WorkerSchedulerProxy
   }
 
   // Accessed only during init.
-  std::unique_ptr<ukm::UkmRecorder> TakeUkmRecorder() {
+  std::unique_ptr<service_manager::Connector> TakeConnector() {
     DCHECK(!initialized_);
 #if DCHECK_IS_ON()
-    DCHECK(!ukm_recorder_taken_);
-    ukm_recorder_taken_ = true;
+    DCHECK(!connector_taken_);
+    connector_taken_ = true;
 #endif
-    return std::move(ukm_recorder_);
+    return std::move(connector_);
   }
 
   // Accessed only during init.
@@ -94,10 +94,10 @@ class PLATFORM_EXPORT WorkerSchedulerProxy
   base::Optional<FrameOriginType> parent_frame_type_;
   FrameStatus initial_frame_status_ = FrameStatus::kNone;
   ukm::SourceId ukm_source_id_ = ukm::kInvalidSourceId;
-  std::unique_ptr<ukm::UkmRecorder> ukm_recorder_;
+  std::unique_ptr<service_manager::Connector> connector_;
 
 #if DCHECK_IS_ON()
-  bool ukm_recorder_taken_ = false;
+  bool connector_taken_ = false;
 #endif
 
   THREAD_CHECKER(parent_thread_checker_);

third_party/blink/renderer/platform/scheduler/worker/worker_thread_scheduler.cc

@@ -15,6 +15,7 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
+#include "services/metrics/public/cpp/mojo_ukm_recorder.h"
 #include "services/metrics/public/cpp/ukm_builders.h"
 #include "third_party/blink/renderer/platform/histogram.h"
 #include "third_party/blink/renderer/platform/scheduler/child/features.h"
@@ -117,7 +118,10 @@ WorkerThreadScheduler::WorkerThreadScheduler(
       initial_frame_status_(proxy ? proxy->initial_frame_status()
                                   : FrameStatus::kNone),
       ukm_source_id_(proxy ? proxy->ukm_source_id() : ukm::kInvalidSourceId),
-      ukm_recorder_(proxy ? proxy->TakeUkmRecorder() : nullptr) {
+      connector_(proxy ? proxy->TakeConnector() : nullptr) {
+  if (connector_) {
+    ukm_recorder_ = ukm::MojoUkmRecorder::Create(connector_.get());
+  }
   thread_start_time_ = helper()->NowTicks();
   load_tracker_.Resume(thread_start_time_);
   helper()->AddTaskTimeObserver(this);

third_party/blink/renderer/platform/scheduler/worker/worker_thread_scheduler.h

@@ -25,6 +25,10 @@ class SequenceManager;
 }
 }  // namespace base
 
+namespace service_manager {
+class Connector;
+}
+
 namespace ukm {
 class UkmRecorder;
 }
@@ -160,6 +164,7 @@ class PLATFORM_EXPORT WorkerThreadScheduler
   const FrameStatus initial_frame_status_;
 
   const ukm::SourceId ukm_source_id_;
+  std::unique_ptr<service_manager::Connector> connector_;
   std::unique_ptr<ukm::UkmRecorder> ukm_recorder_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerThreadScheduler);