Buffer cross frame paint timing updates.

chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h

Index: chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h
diff --git a/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h b/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h
index 5d4cd7daacc48baf76cdcf207707240323f5dc9d..79c2ce5eb0da82b0a20209301da41a2865e7df04 100644
--- a/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h
+++ b/chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h
@@ -9,6 +9,8 @@
 #include "base/test/histogram_tester.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
+#include "chrome/common/page_load_metrics/test/page_load_metrics_test_util.h"
+#include "chrome/common/page_load_metrics/test/weak_mock_timer.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
 #include "content/public/test/web_contents_tester.h"
@@ -21,15 +23,12 @@ namespace page_load_metrics {
 // an observer, override RegisterObservers and call tracker->AddObserver. This
 // will attach the observer to all main frame navigations.
 class PageLoadMetricsObserverTestHarness
-    : public ChromeRenderViewHostTestHarness {
+    : public ChromeRenderViewHostTestHarness,
+      public test::WeakMockTimerProvider {
  public:
   PageLoadMetricsObserverTestHarness();
   ~PageLoadMetricsObserverTestHarness() override;
 
-  // Helper that fills in any timing fields that MWCO requires but that are
-  // currently missing.
-  static void PopulateRequiredTimingFields(mojom::PageLoadTiming* inout_timing);
-
   void SetUp() override;
 
   virtual void RegisterObservers(PageLoadTracker* tracker) {}