[Media Feeds] Add Media.Feed.Discover UKM event

Add a Media.Feed.Discover UKM event that is recorded
when we discover a new Media Feed. This is to track
usage of the feature.

BUG=1065014

Change-Id: If0fb31dcf597cc51716c1397904412f199c09524
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2122368
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#763486}

chrome/browser/media/feeds/media_feeds_browsertest.cc

@@ -21,12 +21,14 @@
 #include "chrome/browser/ui/browser.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "components/ukm/test_ukm_recorder.h"
 #include "content/public/test/frame_load_waiter.h"
 #include "content/public/test/test_utils.h"
 #include "media/base/media_switches.h"
 #include "net/dns/mock_host_resolver.h"
 #include "net/test/embedded_test_server/http_request.h"
 #include "net/test/embedded_test_server/http_response.h"
+#include "services/metrics/public/cpp/ukm_builders.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace media_feeds {
@@ -292,6 +294,8 @@ INSTANTIATE_TEST_SUITE_P(
             false}));
 
 IN_PROC_BROWSER_TEST_P(MediaFeedsDiscoveryBrowserTest, Discover) {
+  ukm::TestAutoSetUkmRecorder ukm_recorder;
+
   DiscoverFeed();
 
   // Check we discovered the feed.
@@ -300,6 +304,19 @@ IN_PROC_BROWSER_TEST_P(MediaFeedsDiscoveryBrowserTest, Discover) {
   if (GetParam().discovered)
     expected_urls.insert(GetServer()->GetURL("/test"));
   EXPECT_EQ(expected_urls, GetDiscoveredFeedURLs());
+
+  // Check that we did/didn't record this to UKM.
+  using Entry = ukm::builders::Media_Feed_Discover;
+  auto entries = ukm_recorder.GetEntriesByName(Entry::kEntryName);
+
+  if (GetParam().discovered) {
+    EXPECT_EQ(1u, entries.size());
+    ukm_recorder.ExpectEntrySourceHasUrl(
+        entries[0], GetServer()->GetURL(kMediaFeedsTestURL));
+    ukm_recorder.ExpectEntryMetric(entries[0], Entry::kHasMediaFeedName, 1);
+  } else {
+    EXPECT_TRUE(entries.empty());
+  }
 }
 
 }  // namespace media_feeds

chrome/browser/media/feeds/media_feeds_contents_observer.cc

@@ -12,6 +12,9 @@
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "mojo/public/cpp/bindings/associated_remote.h"
+#include "services/metrics/public/cpp/ukm_builders.h"
+#include "services/metrics/public/cpp/ukm_entry_builder.h"
+#include "services/metrics/public/cpp/ukm_recorder.h"
 #include "third_party/blink/public/common/associated_interfaces/associated_interface_provider.h"
 #include "url/origin.h"
 
@@ -70,6 +73,15 @@ void MediaFeedsContentsObserver::DidFindMediaFeed(
 
     CHECK(url->SchemeIsCryptographic());
     service->DiscoverMediaFeed(*url);
+
+    ukm::UkmRecorder* ukm_recorder = ukm::UkmRecorder::Get();
+    if (!ukm_recorder)
+      return;
+
+    ukm::builders::Media_Feed_Discover(
+        web_contents()->GetMainFrame()->GetPageUkmSourceId())
+        .SetHasMediaFeed(true)
+        .Record(ukm_recorder);
   }
 
   if (test_closure_)

tools/metrics/ukm/ukm.xml

@@ -5652,6 +5652,21 @@ be describing additional metrics about the same event.
   <metric name="Length"/>
 </event>
 
+<event name="Media.Feed.Discover">
+  <owner>beccahughes@chromium.org</owner>
+  <owner>media-dev@chromium.org</owner>
+  <summary>
+    Media Feeds are out of band feeds of media recommendations that are fetched
+    by the browser. This records when we discover a feed that has been placed in
+    a meta tag on a website.
+  </summary>
+  <metric name="HasMediaFeed">
+    <summary>
+      Whether the site has a media feed.
+    </summary>
+  </metric>
+</event>
+
 <event name="Media.GlobalMediaControls.ActionButtonPressed">
   <owner>steimel@chromium.org</owner>
   <owner>media-dev@chromium.org</owner>