Buffer cross frame paint timing updates.

chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h"
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
@@ skipping 20 matching lines @@
       : test_(test) {}
 
   bool IsNewTabPageUrl(const GURL& url) override { return false; }
 
   // Forward the registration logic to the test class so that derived classes
   // can override the logic there without depending on the embedder interface.
   void RegisterObservers(PageLoadTracker* tracker) override {
     test_->RegisterObservers(tracker);
   }
 
+  std::unique_ptr<base::Timer> CreateTimer() override {
+    std::unique_ptr<WeakMockTimer> timer = base::MakeUnique<WeakMockTimer>();

[Charlie Harrison, 2017/05/30 14:49:07]

nit: usually base::MakeUnique is paired with auto:
auto timer = base::MakeUnique<WeakMockTimer>() to avoid type stuttering.

[Bryan McQuade, 2017/05/30 15:30:22]

done

+    test_->SetMockTimer(timer->AsWeakPtr());
+    return std::move(timer);
+  }
+
  private:
   PageLoadMetricsObserverTestHarness* test_;
 
   DISALLOW_COPY_AND_ASSIGN(TestPageLoadMetricsEmbedderInterface);
 };
 
 }  // namespace
 
 PageLoadMetricsObserverTestHarness::PageLoadMetricsObserverTestHarness()
     : ChromeRenderViewHostTestHarness() {}
@@ skipping 88 matching lines @@
 
 void PageLoadMetricsObserverTestHarness::SimulateTimingUpdate(
     const mojom::PageLoadTiming& timing) {
   SimulateTimingAndMetadataUpdate(timing, mojom::PageLoadMetadata());
 }
 
 void PageLoadMetricsObserverTestHarness::SimulateTimingAndMetadataUpdate(
     const mojom::PageLoadTiming& timing,
     const mojom::PageLoadMetadata& metadata) {
   observer_->OnTimingUpdated(web_contents()->GetMainFrame(), timing, metadata);
+  // If sending the timing update caused the PageLoadMetricsUpdateDispatcher to
+  // schedule a buffering timer, then fire it now so metrics are dispatched to
+  // observers.
+  base::MockTimer* mock_timer = GetMockTimer();
+  if (mock_timer && mock_timer->IsRunning())
+    mock_timer->Fire();
 }
 
 void PageLoadMetricsObserverTestHarness::SimulateStartedResource(
     const ExtraRequestStartInfo& info) {
   observer_->OnRequestStarted(content::GlobalRequestID(), info.resource_type,
                               base::TimeTicks::Now());
 }
 
 void PageLoadMetricsObserverTestHarness::SimulateLoadedResource(
     const ExtraRequestCompleteInfo& info) {
@@ skipping 40 matching lines @@
 }
 
 void PageLoadMetricsObserverTestHarness::NavigateWithPageTransitionAndCommit(
     const GURL& url,
     ui::PageTransition transition) {
   controller().LoadURL(url, content::Referrer(), transition, std::string());
   content::WebContentsTester::For(web_contents())->CommitPendingNavigation();
 }
 
 }  // namespace page_load_metrics