Add support for tracking loading behavior of child frames.

chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc

Index: chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc
diff --git a/chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc b/chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc
index b2e041f94b915e644bbe5ac495db7b5fd1f89541..6142b1d2ff2bf799517a5b5e853a19bf5039b458 100644
--- a/chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc
+++ b/chrome/renderer/page_load_metrics/metrics_render_frame_observer_unittest.cc
@@ -41,26 +41,40 @@ class TestMetricsRenderFrameObserver : public MetricsRenderFrameObserver {
     mock_timer_ = std::move(timer);
   }
 
+  void set_is_main_frame(bool is_main_frame) { is_main_frame_ = is_main_frame; }
+
+  bool WasFakeTimingConsumed() const { return fake_timing_.IsEmpty(); }
+
   void ExpectPageLoadTiming(const PageLoadTiming& timing) {
+    SetFakePageLoadTiming(timing);
     fake_timing_ipc_sender_.ExpectPageLoadTiming(timing);
   }
 
+  void SetFakePageLoadTiming(const PageLoadTiming& timing) {
+    EXPECT_TRUE(fake_timing_.IsEmpty());
+    fake_timing_ = timing;
+  }
+
   PageLoadTiming GetTiming() const override {
-    return fake_timing_ipc_sender_.expected_timings().empty()
-               ? PageLoadTiming()
-               : fake_timing_ipc_sender_.expected_timings().back();
+    PageLoadTiming tmp = fake_timing_;
+    fake_timing_ = PageLoadTiming();
+    return tmp;
   }
 
   void VerifyExpectedTimings() const {
+    EXPECT_TRUE(fake_timing_.IsEmpty());
     fake_timing_ipc_sender_.VerifyExpectedTimings();
   }
 
   bool ShouldSendMetrics() const override { return true; }
   bool HasNoRenderFrame() const override { return false; }
+  bool IsMainFrame() const override { return is_main_frame_; }
 
  private:
   FakePageTimingMetricsIPCSender fake_timing_ipc_sender_;
+  mutable PageLoadTiming fake_timing_;
   mutable std::unique_ptr<base::Timer> mock_timer_;
+  bool is_main_frame_ = true;
 };
 
 typedef testing::Test MetricsRenderFrameObserverTest;
@@ -192,4 +206,24 @@ TEST_F(MetricsRenderFrameObserverTest, MultipleNavigations) {
   mock_timer2->Fire();
 }
 
+TEST_F(MetricsRenderFrameObserverTest, NoUpdatesFromChildFrames) {
+  base::Time nav_start = base::Time::FromDoubleT(10);
+
+  TestMetricsRenderFrameObserver observer;
+  base::MockTimer* mock_timer = new base::MockTimer(false, false);
+  observer.set_mock_timer(base::WrapUnique(mock_timer));
+  observer.set_is_main_frame(false);
+
+  PageLoadTiming timing;
+  timing.navigation_start = nav_start;
+  observer.SetFakePageLoadTiming(timing);
+  observer.DidCommitProvisionalLoad(true, false);
+  ASSERT_FALSE(observer.WasFakeTimingConsumed());
+  ASSERT_FALSE(mock_timer->IsRunning());
+
+  observer.DidChangePerformanceTiming();
+  ASSERT_FALSE(observer.WasFakeTimingConsumed());
+  ASSERT_FALSE(mock_timer->IsRunning());
+}
+
 }  // namespace page_load_metrics