Update from https://crrev.com/306655

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index 80e9f114b9c3a96da2597ba5354c40a2bc3e66b1..9f0867718e2946dca50af24c2eba8af937770b32 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -91,7 +91,7 @@ class ExternalBeginFrameSourceForTest
 
   void TestOnBeginFrame() {
     DCHECK(CalledOnValidThread());
-    CallOnBeginFrame(CreateBeginFrameArgsForTesting());
+    CallOnBeginFrame(CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
   }
 
  private:
@@ -153,6 +153,11 @@ class ThreadProxyForTest : public ThreadProxy {
     test_hooks_->ScheduledActionBeginOutputSurfaceCreation();
   }
 
+  void ScheduledActionManageTiles() override {
+    ThreadProxy::ScheduledActionManageTiles();
+    test_hooks_->ScheduledActionManageTiles();
+  }
+
   ThreadProxyForTest(
       TestHooks* test_hooks,
       LayerTreeHost* host,
@@ -780,6 +785,11 @@ void LayerTreeTest::RunTestWithImplSidePainting() {
   RunTest(true, false, true);
 }
 
+void LayerTreeTest::RunTestWithMainThreadLowLatency() {
+  settings_.main_thread_should_always_be_low_latency = true;
+  RunTest(false, false, false);
+}
+
 void LayerTreeTest::RequestNewOutputSurface(bool fallback) {
   layer_tree_host_->SetOutputSurface(CreateOutputSurface(fallback));
 }