Let blink scheduler know when background parsing a document

components/scheduler/renderer/web_view_scheduler_impl_unittest.cc

Index: components/scheduler/renderer/web_view_scheduler_impl_unittest.cc
diff --git a/components/scheduler/renderer/web_view_scheduler_impl_unittest.cc b/components/scheduler/renderer/web_view_scheduler_impl_unittest.cc
index 49bed4d1dd5cac814544cb7738b094ed6336ad51..a9e2167ad157a9f9a9bd298fe639adabac93d578 100644
--- a/components/scheduler/renderer/web_view_scheduler_impl_unittest.cc
+++ b/components/scheduler/renderer/web_view_scheduler_impl_unittest.cc
@@ -550,4 +550,23 @@ TEST_F(WebViewSchedulerImplTest, RedundantDidStopLoadingCallsAreHarmless) {
   EXPECT_TRUE(web_view_scheduler_->virtualTimeAllowedToAdvance());
 }
 
+TEST_F(WebViewSchedulerImplTest,
+    BackgroundParser_PAUSE_IF_NETWORK_FETCHES_PENDING) {
+  web_view_scheduler_->setVirtualTimePolicy(
+      VirtualTimePolicy::PAUSE_IF_NETWORK_FETCHES_PENDING);
+  EXPECT_TRUE(web_view_scheduler_->virtualTimeAllowedToAdvance());
+
+  web_view_scheduler_->IncrementBackgroundParserCount();
+  EXPECT_FALSE(web_view_scheduler_->virtualTimeAllowedToAdvance());
+
+  web_view_scheduler_->IncrementBackgroundParserCount();
+  EXPECT_FALSE(web_view_scheduler_->virtualTimeAllowedToAdvance());
+
+  web_view_scheduler_->DecrementBackgroundParserCount();
+  EXPECT_FALSE(web_view_scheduler_->virtualTimeAllowedToAdvance());
+
+  web_view_scheduler_->DecrementBackgroundParserCount();
+  EXPECT_TRUE(web_view_scheduler_->virtualTimeAllowedToAdvance());
+}
+
 }  // namespace scheduler