Add PLMObserver::FlushMetricsOnAppEnterBackground.

chrome/browser/page_load_metrics/metrics_web_contents_observer_unittest.cc

 // Copyright (c) 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/metrics_web_contents_observer.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 41 matching lines @@
   void OnTimingUpdate(const PageLoadTiming& timing,
                       const PageLoadExtraInfo& extra_info) override {
     updated_timings_->push_back(timing);
   }
 
   void OnComplete(const PageLoadTiming& timing,
                   const PageLoadExtraInfo& extra_info) override {
     complete_timings_->push_back(timing);
   }
 
+  ObservePolicy FlushMetricsOnAppEnterBackground(
+      const PageLoadTiming& timing,
+      const PageLoadExtraInfo& extra_info) override {
+    return STOP_OBSERVING;
+  }
+
  private:
   std::vector<PageLoadTiming>* const updated_timings_;
   std::vector<PageLoadTiming>* const complete_timings_;
   std::vector<GURL>* const observed_committed_urls_;
 };
 
 class TestPageLoadMetricsEmbedderInterface
     : public PageLoadMetricsEmbedderInterface {
  public:
   TestPageLoadMetricsEmbedderInterface()
@@ skipping 105 matching lines @@
 
  private:
   int num_errors_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsWebContentsObserverTest);
 };
 
 TEST_F(MetricsWebContentsObserverTest, SuccessfulMainFrameNavigation) {
   PageLoadTiming timing;
   timing.navigation_start = base::Time::FromDoubleT(1);
-  timing.response_start = base::TimeDelta::FromMilliseconds(2);
 
   content::WebContentsTester* web_contents_tester =
       content::WebContentsTester::For(web_contents());
 
   ASSERT_TRUE(observed_committed_urls_from_on_start().empty());
   web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl));
   ASSERT_EQ(1u, observed_committed_urls_from_on_start().size());
   ASSERT_TRUE(observed_committed_urls_from_on_start().at(0).is_empty());
 
   ASSERT_EQ(0, CountUpdatedTimingReported());
@@ skipping 293 matching lines @@
 
   observer_->FlushMetricsOnAppEnterBackground();
 
   histogram_tester_.ExpectTotalCount(
       internal::kPageLoadCompletedAfterAppBackground, 1);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, false, 1);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, true, 0);
 
+  // Navigate again, which forces completion callbacks on the previous
+  // navigation to be invoked.
+  web_contents_tester->NavigateAndCommit(GURL(kDefaultTestUrl2));
+
+  // Verify that, even though the page load completed, no complete timings were
+  // reported, because the TestPageLoadMetricsObserver's
+  // FlushMetricsOnAppEnterBackground implementation returned STOP_OBSERVING,
+  // thus preventing OnComplete from being invoked.
+  ASSERT_EQ(0, CountCompleteTimingReported());
+
   DeleteContents();
 
   histogram_tester_.ExpectTotalCount(
       internal::kPageLoadCompletedAfterAppBackground, 2);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, false, 1);
   histogram_tester_.ExpectBucketCount(
       internal::kPageLoadCompletedAfterAppBackground, true, 1);
 }
 
 }  // namespace page_load_metrics