[Cast] Add UKM Metrics for Site-initiated Mirroring

Add UKM metrics to record the website that initiated a mirroring session
and whether audio playback happens on the sender device (used on Meet)
or the receiver device (used on Slides).

Bug: b/158093883, 1095967
Change-Id: I79ddbc7b3e20b39ad68dc2e821005d0c7d550fca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2251201Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Takumi Fujimoto <takumif@chromium.org>
Commit-Queue: Muyao Xu <muyaoxu@google.com>
Cr-Commit-Position: refs/heads/master@{#782615}

chrome/browser/media/router/mojo/media_router_mojo_impl.cc

@@ -33,6 +33,7 @@
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/media_router/media_source.h"
+#include "chrome/common/media_router/providers/cast/cast_media_source.h"
 #include "chrome/grit/chromium_strings.h"
 #include "components/sessions/content/session_tab_helper.h"
 #include "content/public/browser/browser_task_traits.h"
@@ -296,6 +297,11 @@ void MediaRouterMojoImpl::CreateRoute(const MediaSource::Id& source_id,
     MediaRouterMojoMetrics::RecordTabMirroringMetrics(web_contents);
   }
 
+  if (IsSiteInitiatedMirroringSource(source_id)) {
+    MediaRouterMojoMetrics::RecordSiteInitiatedMirroringStarted(web_contents,
+                                                                source);
+  }
+
   MediaRouterMetrics::RecordMediaSinkType(sink->icon_type());
   const MediaRouteProviderId provider_id = FixProviderId(sink->provider_id());
 

chrome/browser/media/router/mojo/media_router_mojo_metrics.cc

@@ -8,6 +8,7 @@
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/version.h"
+#include "chrome/common/media_router/providers/cast/cast_media_source.h"
 #include "components/ukm/content/source_url_recorder.h"
 #include "components/version_info/version_info.h"
 #include "extensions/common/extension.h"
@@ -137,6 +138,20 @@ void MediaRouterMojoMetrics::RecordTabMirroringMetrics(
       .Record(ukm::UkmRecorder::Get());
 }
 
+// static
+void MediaRouterMojoMetrics::RecordSiteInitiatedMirroringStarted(
+    content::WebContents* web_contents,
+    const MediaSource& media_source) {
+  ukm::SourceId source_id =
+      ukm::GetSourceIdForWebContentsDocument(web_contents);
+  auto cast_source = CastMediaSource::FromMediaSource(media_source);
+  if (cast_source) {
+    ukm::builders::MediaRouter_SiteInitiatedMirroringStarted(source_id)
+        .SetAllowAudioCapture(cast_source->allow_audio_capture())
+        .Record(ukm::UkmRecorder::Get());
+  }
+}
+
 // static
 MediaRouteProviderVersion MediaRouterMojoMetrics::GetMediaRouteProviderVersion(
     const base::Version& extension_version,

chrome/browser/media/router/mojo/media_router_mojo_metrics.h

@@ -8,6 +8,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/time/time.h"
 #include "chrome/common/media_router/media_route_provider_helper.h"
+#include "chrome/common/media_router/media_source.h"
 #include "chrome/common/media_router/route_request_result.h"
 #include "content/public/browser/web_contents.h"
 
@@ -127,6 +128,11 @@ class MediaRouterMojoMetrics {
   // tab-mirrored.
   static void RecordTabMirroringMetrics(content::WebContents* web_contents);
 
+  // Records the audio capture setting of a site-initiated mirroring session.
+  static void RecordSiteInitiatedMirroringStarted(
+      content::WebContents* web_contents,
+      const MediaSource& media_source);
+
  private:
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoMetricsTest,
                            TestGetMediaRouteProviderVersion);

tools/metrics/ukm/ukm.xml

@@ -6359,6 +6359,29 @@ be describing additional metrics about the same event.
   </metric>
 </event>
 
+<event name="MediaRouter.SiteInitiatedMirroringStarted">
+  <owner>muyaoxu@google.com</owner>
+  <owner>openscreen-eng@google.com</owner>
+  <summary>
+    Recorded whenever user starts a site-initiated mirroring session via Media
+    Router.
+  </summary>
+  <metric name="AllowAudioCapture" enum="BooleanAllowed">
+    <summary>
+      Whether audio capture is allowed in the cast session. If allowed, audio
+      playback will happen on the receiver side. If not allowed, audio playback
+      will happen on the sender side.
+    </summary>
+    <aggregation>
+      <history>
+        <statistics>
+          <enumeration/>
+        </statistics>
+      </history>
+    </aggregation>
+  </metric>
+</event>
+
 <event name="MediaRouter.TabMirroringStarted">
   <owner>takumif@chromium.org</owner>
   <owner>openscreen-eng@google.com</owner>