Make rendering timeouts work even if paint data received early

content/browser/renderer_host/render_widget_host_unittest.cc

Index: content/browser/renderer_host/render_widget_host_unittest.cc
diff --git a/content/browser/renderer_host/render_widget_host_unittest.cc b/content/browser/renderer_host/render_widget_host_unittest.cc
index 0e2557c36cdc1d67320e5e09aeae13de283e4de6..785288d5c6e2b48d2416037bc03ae731b2360040 100644
--- a/content/browser/renderer_host/render_widget_host_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_unittest.cc
@@ -1106,7 +1106,18 @@ TEST_F(RenderWidgetHostTest, NewContentRenderingTimeout) {
 
   // Test immediate start and stop, ensuring that the timeout doesn't fire.
   host_->StartNewContentRenderingTimeout();
-  host_->StopNewContentRenderingTimeout();
+  host_->OnFirstPaintAfterLoad();
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE, base::MessageLoop::QuitClosure(),
+      TimeDelta::FromMicroseconds(20));

[esprehn, 2015/10/02 05:58:15]

Why wait 20 microseconds? This usually produces flake in tests

[kenrb, 2015/10/02 13:24:40]

I used the same values as the hung renderer test, but I've changed it to 200.

+  base::MessageLoop::current()->Run();
+
+  EXPECT_FALSE(host_->new_content_rendering_timeout_fired());
+
+  // Test that the timer doesn't fire if it receives a stop before
+  // a start.
+  host_->OnFirstPaintAfterLoad();
+  host_->StartNewContentRenderingTimeout();
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::MessageLoop::QuitClosure(),
       TimeDelta::FromMicroseconds(20));