Fix flakiness in page_load_metrics_browser_test

chrome/browser/page_load_metrics/page_load_metrics_browsertest.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 "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/test/histogram_tester.h"
 #include "base/time/time.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/document_write_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/no_state_prefetch_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
 #include "chrome/browser/prerender/prerender_histograms.h"
 #include "chrome/browser/prerender/prerender_origin.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_navigator_params.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/page_load_metrics/page_load_metrics_messages.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/prefs/pref_service.h"
+#include "content/public/browser/browser_message_filter.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/download_test_observer.h"
+#include "ipc/ipc_message_start.h"
 #include "net/http/failing_http_transaction_factory.h"
 #include "net/http/http_cache.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "net/test/url_request/url_request_failed_job.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 
+namespace {
+
+// Waits until a PageLoadMetricsMsg_TimingUpdated message IPC is received.
+class TimingUpdatedObserver : public content::BrowserMessageFilter {
+ public:
+  explicit TimingUpdatedObserver(content::RenderWidgetHost* render_widget_host)
+      : content::BrowserMessageFilter(PageLoadMetricsMsgStart) {
+    render_widget_host->GetProcess()->AddFilter(this);
+
+    // Roudtrip to the IO thread, to ensure that the filter is properly
+    // installed.
+    content::BrowserThread::PostTaskAndReply(
+        content::BrowserThread::IO, FROM_HERE, base::Bind(&base::DoNothing),
+        base::Bind(&TimingUpdatedObserver::Quit, this));
+    run_loop_.reset(new base::RunLoop());
+    run_loop_->Run();
+    run_loop_.reset(nullptr);
+  }
+
+  // Waits for the IPC. Returns immediately if the IPC has already been received
+  // before this call.
+  void WaitForTimingUpdatedIPC() {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    if (timing_updated_)
+      return;
+
+    run_loop_.reset(new base::RunLoop());
+    run_loop_->Run();
+    run_loop_.reset(nullptr);
+  }
+
+ private:
+  bool OnMessageReceived(const IPC::Message& message) override {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+
+    if (message.type() == PageLoadMetricsMsg_TimingUpdated::ID) {
+      content::BrowserThread::PostTask(
+          content::BrowserThread::UI, FROM_HERE,
+          base::Bind(&TimingUpdatedObserver::SetTimingUpdatedAndQuit, this));
+    }
+
+    return false;
+  }
+
+  void Quit() {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    if (run_loop_)
+      run_loop_->Quit();
+  }
+
+  void SetTimingUpdatedAndQuit() {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    timing_updated_ = true;
+    Quit();
+  }
+
+  ~TimingUpdatedObserver() override {}
+
+  std::unique_ptr<base::RunLoop> run_loop_;
+  bool timing_updated_ = false;
+};
+
+}  // namespace
+
 class PageLoadMetricsBrowserTest : public InProcessBrowserTest {
  public:
   PageLoadMetricsBrowserTest() {}
   ~PageLoadMetricsBrowserTest() override {}
 
  protected:
   void NavigateToUntrackedUrl() {
     ui_test_utils::NavigateToURL(browser(), GURL(url::kAboutBlankURL));
   }
 
   bool NoPageLoadMetricsRecorded() {
     return histogram_tester_.GetTotalCountsForPrefix("PageLoad.").empty();
   }
 
+  void WaitForTimingUpdatedIPC() {
+    content::WebContents* web_contents =
+        browser()->tab_strip_model()->GetActiveWebContents();
+    scoped_refptr<TimingUpdatedObserver> observer(new TimingUpdatedObserver(
+        web_contents->GetRenderViewHost()->GetWidget()));
+
+    // The observer must be created before checking this, to avoid a race
+    // condition.
+    if (!NoPageLoadMetricsRecorded())
+      return;
+
+    observer->WaitForTimingUpdatedIPC();
+  }
+
   base::HistogramTester histogram_tester_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadMetricsBrowserTest);
 };
 
 void FailAllNetworkTransactions(net::URLRequestContextGetter* getter) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   net::HttpCache* cache(
       getter->GetURLRequestContext()->http_transaction_factory()->GetCache());
   DCHECK(cache);
@@ skipping 10 matching lines @@
   EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NewPage) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(internal::kHistogramDomContentLoaded, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramLoad, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramParseDuration, 1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseBlockedOnScriptLoad, 1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseBlockedOnScriptExecution, 1);
 
   // Verify that NoPageLoadMetricsRecorded returns false when PageLoad metrics
   // have been recorded.
   EXPECT_FALSE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SamePageNavigation) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL("/title1.html#hash"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(internal::kHistogramDomContentLoaded, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramLoad, 1);
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, SameUrlNavigation) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   NavigateToUntrackedUrl();
 
   // We expect one histogram sample for each navigation to title1.html.
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(internal::kHistogramDomContentLoaded, 2);
   histogram_tester_.ExpectTotalCount(internal::kHistogramLoad, 2);
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 2);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHtmlMainResource) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/circle.svg"));
@@ skipping 66 matching lines @@
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, PreloadDocumentWrite) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_external_script.html"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteParseStartToFirstContentfulPaint, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoPreloadDocumentWrite) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_no_script.html"));
@@ skipping 16 matching lines @@
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteBlock) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_script_block.html"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, DocumentWriteReload) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_script_block.html"));
 
   // Reload should not log the histogram as the script is not blocked.
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_script_block.html"));
 
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL(
                      "/page_load_metrics/document_write_script_block.html"));
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
 
   NavigateToUntrackedUrl();
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockParseStartToFirstContentfulPaint, 1);
 
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramDocWriteBlockReloadCount, 2);
@@ skipping 41 matching lines @@
   // When an XHTML page contains invalid XML, it causes a paint of the error
   // message without a layout. Page load metrics currently treats this as an
   // error. Eventually, we'll fix this by special casing the handling of
   // documents with non-well-formed XML on the blink side. See crbug.com/627607
   // for more.
   ui_test_utils::NavigateToURL(
       browser(),
       embedded_test_server()->GetURL("/page_load_metrics/badxml.xhtml"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 0);
   histogram_tester_.ExpectTotalCount(internal::kHistogramFirstPaint, 0);
   histogram_tester_.ExpectBucketCount(page_load_metrics::internal::kErrorEvents,
                                       page_load_metrics::ERR_BAD_TIMING_IPC, 1);
 }
 
 // Test code that aborts provisional navigations.
 // TODO(csharrison): Move these to unit tests once the navigation API in content
 // properly calls NavigationHandle/NavigationThrottle methods.
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortNewNavigation) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
   chrome::NavigateParams params(browser(), url, ui::PAGE_TRANSITION_LINK);
   content::TestNavigationManager manager(
       browser()->tab_strip_model()->GetActiveWebContents(), url);
 
   chrome::Navigate(&params);
   EXPECT_TRUE(manager.WaitForRequestStart());
 
   GURL url2(embedded_test_server()->GetURL("/title2.html"));
   chrome::NavigateParams params2(browser(), url2,
                                  ui::PAGE_TRANSITION_FROM_ADDRESS_BAR);
   content::TestNavigationManager manager2(
       browser()->tab_strip_model()->GetActiveWebContents(), url2);
   chrome::Navigate(&params2);
 
   manager2.WaitForNavigationFinished();
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramAbortNewNavigationBeforeCommit, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortReload) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
   chrome::NavigateParams params(browser(), url, ui::PAGE_TRANSITION_LINK);
   content::TestNavigationManager manager(
       browser()->tab_strip_model()->GetActiveWebContents(), url);
 
   chrome::Navigate(&params);
   EXPECT_TRUE(manager.WaitForRequestStart());
 
   chrome::NavigateParams params2(browser(), url, ui::PAGE_TRANSITION_RELOAD);
   content::TestNavigationManager manager2(
       browser()->tab_strip_model()->GetActiveWebContents(), url);
   chrome::Navigate(&params2);
 
   manager2.WaitForNavigationFinished();
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramAbortReloadBeforeCommit, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, AbortClose) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   GURL url(embedded_test_server()->GetURL("/title1.html"));
   chrome::NavigateParams params(browser(), url, ui::PAGE_TRANSITION_LINK);
   content::TestNavigationManager manager(
@@ skipping 62 matching lines @@
   {
     content::TestNavigationManager reload_manager(
         browser()->tab_strip_model()->GetActiveWebContents(), first_url);
     EXPECT_TRUE(content::ExecuteScript(
         browser()->tab_strip_model()->GetActiveWebContents(),
         "window.location.reload();"));
   }
 
   manager.WaitForNavigationFinished();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramAbortClientRedirectBeforeCommit, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
                        FirstMeaningfulPaintRecorded) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
 
   // Wait until the renderer finishes observing layouts.
   const int kNetworkIdleTime = 500;
   const int kMargin = 500;
   const std::string javascript = base::StringPrintf(
       "setTimeout(() => window.domAutomationController.send(true), %d)",
       kNetworkIdleTime + kMargin);
   bool result;
   EXPECT_TRUE(content::ExecuteScriptAndExtractBool(
       browser()->tab_strip_model()->GetActiveWebContents(),
       javascript, &result));
   EXPECT_TRUE(result);
 
   NavigateToUntrackedUrl();
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectUniqueSample(
       internal::kHistogramFirstMeaningfulPaintStatus,
       internal::FIRST_MEANINGFUL_PAINT_RECORDED, 1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramFirstMeaningfulPaint, 1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseStartToFirstMeaningfulPaint, 1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
                        FirstMeaningfulPaintNotRecorded) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
 
   // Navigate away before a FMP is reported.
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectUniqueSample(
       internal::kHistogramFirstMeaningfulPaintStatus,
       internal::FIRST_MEANINGFUL_PAINT_DID_NOT_REACH_NETWORK_STABLE, 1);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramFirstMeaningfulPaint, 0);
   histogram_tester_.ExpectTotalCount(
       internal::kHistogramParseStartToFirstMeaningfulPaint, 0);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
                        NoStatePrefetchObserverCacheable) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       prerender::PrerenderHistograms::GetFirstContentfulPaintHistogramName(
           prerender::ORIGIN_NONE, false, true, base::TimeDelta()),
       0);
   histogram_tester_.ExpectTotalCount(
       prerender::PrerenderHistograms::GetFirstContentfulPaintHistogramName(
           prerender::ORIGIN_NONE, false, false, base::TimeDelta()),
       1);
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest,
                        NoStatePrefetchObserverNoStore) {
   ASSERT_TRUE(embedded_test_server()->Start());
 
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/nostore.html"));
   NavigateToUntrackedUrl();
 
+  WaitForTimingUpdatedIPC();
   histogram_tester_.ExpectTotalCount(
       prerender::PrerenderHistograms::GetFirstContentfulPaintHistogramName(
           prerender::ORIGIN_NONE, false, true, base::TimeDelta()),
       1);
   histogram_tester_.ExpectTotalCount(
       prerender::PrerenderHistograms::GetFirstContentfulPaintHistogramName(
           prerender::ORIGIN_NONE, false, false, base::TimeDelta()),
       0);
 }