Add UseCounters for Conversion Measurement API

Adds Blink Usecounters for impression registration, conversion
registration, and a composite usecounter for both of those events.
These are necessary to measure the percentage of page loads using the
API, for running an origin trial.

A new test harness is added in the chrome/ layer to verify that
metrics are recorded as expected.

Bug: 1109079
Change-Id: I2f70bb3a2eac60ff45a5654169b4db959fd1d3f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2314843
Commit-Queue: John Delaney <johnidel@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792856}

chrome/browser/conversions/OWNERS

+file://content/browser/conversions/OWNERS

chrome/browser/conversions/conversions_usecounter_browsertest.cc

+// Copyright 2020 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/test/metrics/histogram_tester.h"
+#include "base/test/scoped_feature_list.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/test/browser_test.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/test_navigation_observer.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/test/embedded_test_server/default_handlers.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Tests UseCounters recorded for the Conversion Measurement API. This is tested
+// in the Chrome layer, as UseCounter recording is not used with content shell.
+class ConversionsUseCounterBrowsertest : public InProcessBrowserTest {
+ public:
+  ConversionsUseCounterBrowsertest() = default;
+
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    // Sets up the blink runtime feature for ConversionMeasurement.
+    command_line->AppendSwitch(
+        switches::kEnableExperimentalWebPlatformFeatures);
+  }
+
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+    server_.SetSSLConfig(net::EmbeddedTestServer::CERT_TEST_NAMES);
+    net::test_server::RegisterDefaultHandlers(&server_);
+    server_.ServeFilesFromSourceDirectory("content/test/data");
+    content::SetupCrossSiteRedirector(&server_);
+    ASSERT_TRUE(server_.Start());
+  }
+
+ protected:
+  net::EmbeddedTestServer server_{net::EmbeddedTestServer::TYPE_HTTPS};
+};
+
+IN_PROC_BROWSER_TEST_F(ConversionsUseCounterBrowsertest,
+                       ImpressionClicked_FeatureRecorded) {
+  base::HistogramTester histogram_tester;
+
+  EXPECT_TRUE(ui_test_utils::NavigateToURL(
+      browser(),
+      server_.GetURL("a.test",
+                     "/conversions/page_with_impression_creator.html")));
+
+  content::WebContents* web_contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+
+  // Create an anchor tag with impression attributes and click the link. By
+  // default the target is set to "_top".
+  EXPECT_TRUE(ExecJs(web_contents, R"(
+    createImpressionTag("link" /* id */,
+                        "https://a.com" /* url */,
+                        "1" /* impression data */,
+                        "https://a.com" /* conversion_destination */);)"));
+
+  content::TestNavigationObserver observer(web_contents);
+  EXPECT_TRUE(ExecJs(web_contents, "simulateClick('link');"));
+  observer.Wait();
+
+  histogram_tester.ExpectBucketCount(
+      "Blink.UseCounter.Features",
+      blink::mojom::WebFeature::kImpressionRegistration, 1);
+  histogram_tester.ExpectBucketCount(
+      "Blink.UseCounter.Features", blink::mojom::WebFeature::kConversionAPIAll,
+      1);
+}
+
+IN_PROC_BROWSER_TEST_F(ConversionsUseCounterBrowsertest,
+                       ConversionPing_FeatureRecorded) {
+  base::HistogramTester histogram_tester;
+
+  EXPECT_TRUE(ui_test_utils::NavigateToURL(
+      browser(),
+      server_.GetURL("a.test",
+                     "/conversions/page_with_conversion_redirect.html")));
+
+  content::WebContents* web_contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+
+  // Register a conversion with the original page as the reporting origin.
+  EXPECT_TRUE(ExecJs(web_contents, "registerConversion(7)"));
+
+  // Wait for the conversion redirect to be intercepted. This is indicated by
+  // window title changing when the img element for the conversion request fires
+  // an onerror event.
+  const base::string16 kConvertTitle = base::ASCIIToUTF16("converted");
+  content::TitleWatcher watcher(web_contents, kConvertTitle);
+  EXPECT_EQ(kConvertTitle, watcher.WaitAndGetTitle());
+
+  // Navigate to a new page to flush metrics.
+  EXPECT_TRUE(ui_test_utils::NavigateToURL(browser(), GURL("about:blank")));
+
+  histogram_tester.ExpectBucketCount(
+      "Blink.UseCounter.Features",
+      blink::mojom::WebFeature::kConversionRegistration, 1);
+  histogram_tester.ExpectBucketCount(
+      "Blink.UseCounter.Features", blink::mojom::WebFeature::kConversionAPIAll,
+      1);
+}

chrome/test/BUILD.gn

@@ -882,6 +882,7 @@ if (!is_android) {
       "../browser/component_updater/component_patcher_operation_browsertest.cc",
       "../browser/content_index/content_index_browsertest.cc",
       "../browser/content_settings/content_settings_browsertest.cc",
+      "../browser/conversions/conversions_usecounter_browsertest.cc",
       "../browser/crash_recovery_browsertest.cc",
       "../browser/custom_handlers/protocol_handler_registry_browsertest.cc",
       "../browser/data_reduction_proxy/data_reduction_proxy_browsertest.cc",

content/test/data/conversions/register_conversion.js

@@ -12,6 +12,7 @@ function registerConversionForOrigin(data, origin) {
   img.src = origin +
       "/server-redirect?.well-known/register-conversion?conversion-data=" +
       data;
+  img.onerror = function () { document.title = "converted"; };
   document.body.appendChild(img);
 }
 

third_party/blink/public/mojom/web_feature/web_feature.mojom

@@ -2688,6 +2688,9 @@ enum WebFeature {
   kCrossBrowsingContextGroupMainFrameNulledNonEmptyNameAccessed = 3353,
   kPositionSticky = 3354,
   kCommaSeparatorInAllowAttribute = 3355,
+  kConversionAPIAll = 3356,
+  kImpressionRegistration = 3357,
+  kConversionRegistration = 3358,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

third_party/blink/renderer/core/html/html_anchor_element.cc

@@ -423,6 +423,11 @@ base::Optional<WebImpression> HTMLAnchorElement::GetImpressionForNavigation()
       expiry = base::TimeDelta::FromMilliseconds(expiry_milliseconds);
   }
 
+  UseCounter::Count(GetExecutionContext(),
+                    mojom::blink::WebFeature::kConversionAPIAll);
+  UseCounter::Count(GetExecutionContext(),
+                    mojom::blink::WebFeature::kImpressionRegistration);
+
   return WebImpression{conversion_destination, reporting_origin,
                        impression_data, expiry};
 }

third_party/blink/renderer/core/loader/frame_fetch_context.cc

@@ -1085,6 +1085,13 @@ bool FrameFetchContext::SendConversionRequestInsteadOfRedirecting(
   GetFrame()->GetRemoteNavigationAssociatedInterfaces()->GetInterface(
       &conversion_host);
   conversion_host->RegisterConversion(std::move(conversion));
+
+  // Log use counters once we have a conversion.
+  UseCounter::Count(document_->domWindow(),
+                    mojom::blink::WebFeature::kConversionAPIAll);
+  UseCounter::Count(document_->domWindow(),
+                    mojom::blink::WebFeature::kConversionRegistration);
+
   return true;
 }
 

tools/metrics/histograms/enums.xml

@@ -28563,6 +28563,9 @@ Called by update_use_counter_feature_enum.py.-->
       label="CrossBrowsingContextGroupMainFrameNulledNonEmptyNameAccessed"/>
   <int value="3354" label="PositionSticky"/>
   <int value="3355" label="CommaSeparatorInAllowAttribute"/>
+  <int value="3356" label="ConversionAPIAll"/>
+  <int value="3357" label="ImpressionRegistration"/>
+  <int value="3358" label="ConversionRegistration"/>
 </enum>
 
 <enum name="FeaturePolicyAllowlistType">