Prevent tracking metrics for cases such as 204s and downloads.

chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc

Index: chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc b/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
index 6077b6a2abcbb8bbb72cb6d448b736bac50c8b94..b3d4815415ba3f7c3e4e0bc77e334526d37150f2 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_browsertest.cc
@@ -38,6 +38,10 @@ class PageLoadMetricsBrowserTest : public InProcessBrowserTest {
     ui_test_utils::NavigateToURL(browser(), GURL(url::kAboutBlankURL));
   }
 
+  bool NoPageLoadMetricsRecorded() {
+    return histogram_tester_.GetTotalCountsForPrefix("PageLoad.").empty();
+  }
+
   base::HistogramTester histogram_tester_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadMetricsBrowserTest);
@@ -58,11 +62,7 @@ void FailAllNetworkTransactions(net::URLRequestContextGetter* getter) {
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NoNavigation) {
   ASSERT_TRUE(embedded_test_server()->Start());
-
-  histogram_tester_.ExpectTotalCount(internal::kHistogramCommit, 0);
-  histogram_tester_.ExpectTotalCount(internal::kHistogramDomContentLoaded, 0);
-  histogram_tester_.ExpectTotalCount(internal::kHistogramLoad, 0);
-  histogram_tester_.ExpectTotalCount(internal::kHistogramFirstLayout, 0);
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NewPage) {
@@ -80,6 +80,10 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NewPage) {
       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) {
@@ -118,10 +122,7 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHtmlMainResource) {
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/circle.svg"));
   NavigateToUntrackedUrl();
-
-  histogram_tester_.ExpectTotalCount(internal::kHistogramCommit, 0);
-  histogram_tester_.ExpectTotalCount(page_load_metrics::internal::kErrorEvents,
-                                     0);
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHttpOrHttpsUrl) {
@@ -129,10 +130,7 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, NonHttpOrHttpsUrl) {
 
   ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIVersionURL));
   NavigateToUntrackedUrl();
-
-  histogram_tester_.ExpectTotalCount(internal::kHistogramCommit, 0);
-  histogram_tester_.ExpectTotalCount(page_load_metrics::internal::kErrorEvents,
-                                     0);
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, HttpErrorPage) {
@@ -141,10 +139,7 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, HttpErrorPage) {
   ui_test_utils::NavigateToURL(
       browser(), embedded_test_server()->GetURL("/page_load_metrics/404.html"));
   NavigateToUntrackedUrl();
-
-  histogram_tester_.ExpectTotalCount(internal::kHistogramCommit, 0);
-  histogram_tester_.ExpectTotalCount(page_load_metrics::internal::kErrorEvents,
-                                     0);
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, ChromeErrorPage) {
@@ -162,10 +157,25 @@ IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, ChromeErrorPage) {
   ui_test_utils::NavigateToURL(browser(),
                                embedded_test_server()->GetURL("/title1.html"));
   NavigateToUntrackedUrl();
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
+}
 
-  histogram_tester_.ExpectTotalCount(internal::kHistogramCommit, 0);
-  histogram_tester_.ExpectTotalCount(page_load_metrics::internal::kErrorEvents,
-                                     0);
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, Ignore204Pages) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+
+  ui_test_utils::NavigateToURL(browser(),
+                               embedded_test_server()->GetURL("/page204.html"));
+  NavigateToUntrackedUrl();
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
+}
+
+IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, IgnoreDownloads) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+
+  ui_test_utils::NavigateToURL(
+      browser(), embedded_test_server()->GetURL("/download-test3.gif"));
+  NavigateToUntrackedUrl();
+  EXPECT_TRUE(NoPageLoadMetricsRecorded());
 }
 
 IN_PROC_BROWSER_TEST_F(PageLoadMetricsBrowserTest, PreloadDocumentWrite) {