Scheduler: GetFrameScheduler should return FrameSchedulerImpl.

Changes so that MainThreadTaskQueue::GetFrameScheduler can return
FrameSchedulerImpl rather than FrameScheduler.

FakeFrameScheduler should inherit from FrameSchedulerImpl instead
of FrameScheduler.

Change-Id: Ic892ab9132c69d6f3b67f2671dbc09f9f1de2f6c
Reviewed-on: https://chromium-review.googlesource.com/1074648
Commit-Queue: Farah Charab <farahcharab@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562470}

third_party/blink/renderer/platform/scheduler/main_thread/frame_scheduler_impl.cc

@@ -116,23 +116,29 @@ FrameSchedulerImpl::FrameSchedulerImpl(
                              this,
                              &tracing_controller_,
                              YesNoStateToString),
-      page_frozen_for_tracing_(parent_page_scheduler_->IsFrozen(),
-                               "FrameScheduler.PageFrozen",
-                               this,
-                               &tracing_controller_,
-                               FrozenStateToString),
-      page_visibility_for_tracing_(parent_page_scheduler_->IsPageVisible()
-                                       ? PageVisibilityState::kVisible
-                                       : PageVisibilityState::kHidden,
-                                   "FrameScheduler.PageVisibility",
-                                   this,
-                                   &tracing_controller_,
-                                   PageVisibilityStateToString),
-      page_keep_active_for_tracing_(parent_page_scheduler_->KeepActive(),
-                                    "FrameScheduler.KeepActive",
-                                    this,
-                                    &tracing_controller_,
-                                    KeepActiveStateToString) {}
+      page_frozen_for_tracing_(
+          parent_page_scheduler_ ? parent_page_scheduler_->IsFrozen() : true,
+          "FrameScheduler.PageFrozen",
+          this,
+          &tracing_controller_,
+          FrozenStateToString),
+      page_visibility_for_tracing_(
+          parent_page_scheduler_ && parent_page_scheduler_->IsPageVisible()
+              ? PageVisibilityState::kVisible
+              : PageVisibilityState::kHidden,
+          "FrameScheduler.PageVisibility",
+          this,
+          &tracing_controller_,
+          PageVisibilityStateToString),
+      page_keep_active_for_tracing_(
+          parent_page_scheduler_ ? parent_page_scheduler_->KeepActive() : false,
+          "FrameScheduler.KeepActive",
+          this,
+          &tracing_controller_,
+          KeepActiveStateToString) {}
+
+FrameSchedulerImpl::FrameSchedulerImpl()
+    : FrameSchedulerImpl(nullptr, nullptr, nullptr, FrameType::kSubframe) {}
 
 namespace {
 

third_party/blink/renderer/platform/scheduler/main_thread/frame_scheduler_impl.h

@@ -94,6 +94,11 @@ class PLATFORM_EXPORT FrameSchedulerImpl : public FrameScheduler {
   void SetPageKeepActiveForTracing(bool keep_active);
   void SetPageFrozenForTracing(bool frozen);
 
+ protected:
+  // This will construct a subframe that is not linked to any main thread or
+  // page scheduler. Should be used only for testing purposes.
+  FrameSchedulerImpl();
+
  private:
   friend class PageSchedulerImpl;
   friend class main_thread_scheduler_impl_unittest::MainThreadSchedulerImplTest;
@@ -174,7 +179,6 @@ class PLATFORM_EXPORT FrameSchedulerImpl : public FrameScheduler {
       page_visibility_for_tracing_;
   TraceableState<bool, kTracingCategoryNameInfo> page_keep_active_for_tracing_;
 
-
   DISALLOW_COPY_AND_ASSIGN(FrameSchedulerImpl);
 };
 

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_metrics_helper_unittest.cc

@@ -82,7 +82,7 @@ class MainThreadMetricsHelperTest : public testing::Test {
                                        start + duration, base::nullopt);
   }
 
-  void RunTask(FrameScheduler* scheduler,
+  void RunTask(FrameSchedulerImpl* scheduler,
                base::TimeTicks start,
                base::TimeDelta duration) {
     DCHECK_LE(clock_.NowTicks(), start);

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_task_queue.cc

@@ -172,7 +172,7 @@ void MainThreadTaskQueue::ClearReferencesToSchedulers() {
   frame_scheduler_ = nullptr;
 }
 
-FrameScheduler* MainThreadTaskQueue::GetFrameScheduler() const {
+FrameSchedulerImpl* MainThreadTaskQueue::GetFrameScheduler() const {
   return frame_scheduler_;
 }
 
@@ -181,7 +181,7 @@ void MainThreadTaskQueue::DetachFromFrameScheduler() {
 }
 
 void MainThreadTaskQueue::SetFrameSchedulerForTest(
-    FrameScheduler* frame_scheduler) {
+    FrameSchedulerImpl* frame_scheduler) {
   frame_scheduler_ = frame_scheduler;
 }
 

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_task_queue.h

@@ -17,9 +17,6 @@ class TaskQueueManager;
 }  // namespace base
 
 namespace blink {
-
-class FrameScheduler;
-
 namespace scheduler {
 
 class MainThreadSchedulerImpl;
@@ -157,7 +154,7 @@ class PLATFORM_EXPORT MainThreadTaskQueue
     base::sequence_manager::TaskQueue::Spec spec;
     base::Optional<base::sequence_manager::TaskQueue::QueuePriority>
         fixed_priority;
-    FrameScheduler* frame_scheduler;
+    FrameSchedulerImpl* frame_scheduler;
     bool can_be_deferred;
     bool can_be_throttled;
     bool can_be_paused;
@@ -202,11 +199,11 @@ class PLATFORM_EXPORT MainThreadTaskQueue
   // Override base method to notify MainThreadScheduler about shutdown queue.
   void ShutdownTaskQueue() override;
 
-  FrameScheduler* GetFrameScheduler() const;
+  FrameSchedulerImpl* GetFrameScheduler() const;
   void DetachFromFrameScheduler();
 
  protected:
-  void SetFrameSchedulerForTest(FrameScheduler* frame);
+  void SetFrameSchedulerForTest(FrameSchedulerImpl* frame_scheduler);
 
   MainThreadTaskQueue(
       std::unique_ptr<base::sequence_manager::internal::TaskQueueImpl> impl,
@@ -236,7 +233,7 @@ class PLATFORM_EXPORT MainThreadTaskQueue
   // Needed to notify renderer scheduler about completed tasks.
   MainThreadSchedulerImpl* main_thread_scheduler_;  // NOT OWNED
 
-  FrameScheduler* frame_scheduler_;  // NOT OWNED
+  FrameSchedulerImpl* frame_scheduler_;  // NOT OWNED
 
   DISALLOW_COPY_AND_ASSIGN(MainThreadTaskQueue);
 };

third_party/blink/renderer/platform/scheduler/test/fake_frame_scheduler.h

@@ -28,7 +28,7 @@ class MainThreadTaskQueueForTest : public MainThreadTaskQueue {
 };
 
 // A dummy FrameScheduler for tests.
-class FakeFrameScheduler : public FrameScheduler {
+class FakeFrameScheduler : public FrameSchedulerImpl {
  public:
   FakeFrameScheduler()
       : page_scheduler_(nullptr),