Record PendingTaskCount when a backgrounded renderer is suspended.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc

Index: third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
index 8ed739bcce408af3e58d1b9c824b5ba77ed7cc54..c313d0ea2f22498eb3a882937b716710390ff2c3 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl_unittest.cc
@@ -2191,6 +2191,18 @@ TEST_F(RendererSchedulerImplTest, SuspendRenderer) {
               testing::ElementsAre(std::string("L1"), std::string("T1")));
 }
 
+TEST_F(RendererSchedulerImplTest, GetNumberOfPendingTasks) {
+  // Assume that the renderer is backgrounded.
+  scheduler_->OnRendererBackgrounded();
+
+  std::vector<std::string> run_order;
+  PostTestTasks(&run_order, "D1 C1 L1 I1 T1");
+  EXPECT_EQ(5, scheduler_->GetNumberOfPendingTasks());
+  EnableIdleTasks();
+  RunUntilIdle();
+  EXPECT_EQ(0, scheduler_->GetNumberOfPendingTasks());
+}
+
 TEST_F(RendererSchedulerImplTest, UseCaseToString) {
   CheckAllUseCaseToString();
 }