weblayer: wires up ContentStabilityMetricsProvider

This gives the core stability metrics.

BUG=1120537
TEST=covered by weblayer_browsertests

Change-Id: I22e99959dacb9b9593af02cea70088d449e604a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2376565Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801836}

weblayer/BUILD.gn

@@ -386,6 +386,7 @@ source_set("weblayer_lib_base") {
     "//components/keyed_service/content",
     "//components/language/core/browser",
     "//components/metrics",
+    "//components/metrics:content",
     "//components/network_time",
     "//components/omnibox/browser:location_bar",
     "//components/page_info",

weblayer/browser/android/metrics/metrics_browsertest.cc

@@ -145,6 +145,28 @@ IN_PROC_BROWSER_TEST_F(MetricsBrowserTest, PageLoadsEnableMultipleUploads) {
   // might potentially have a third metrics log in the queue.
 }
 
+IN_PROC_BROWSER_TEST_F(MetricsBrowserTest, NavigationIncrementsPageLoadCount) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+  metrics::ChromeUserMetricsExtension log = WaitForNextMetricsLog();
+  // The initial log should not have a page load count (because nothing was
+  // loaded).
+  {
+    const metrics::SystemProfileProto& system_profile = log.system_profile();
+    ASSERT_TRUE(system_profile.has_stability());
+    EXPECT_EQ(0, system_profile.stability().page_load_count());
+  }
+
+  // Loading a page should increment the page load count.
+  NavigateAndWaitForCompletion(
+      embedded_test_server()->GetURL("/simple_page.html"), shell());
+  log = WaitForNextMetricsLog();
+  {
+    const metrics::SystemProfileProto& system_profile = log.system_profile();
+    ASSERT_TRUE(system_profile.has_stability());
+    EXPECT_EQ(1, system_profile.stability().page_load_count());
+  }
+}
+
 IN_PROC_BROWSER_TEST_F(MetricsBrowserTest, RendererHistograms) {
   base::HistogramTester histogram_tester;
   ASSERT_TRUE(embedded_test_server()->Start());

weblayer/browser/android/metrics/weblayer_metrics_service_client.cc

@@ -10,6 +10,8 @@
 
 #include "base/base64.h"
 #include "base/no_destructor.h"
+#include "components/metrics/content/content_stability_metrics_provider.h"
+#include "components/metrics/content/extensions_helper.h"
 #include "components/metrics/metrics_provider.h"
 #include "components/metrics/metrics_service.h"
 #include "components/page_load_metrics/browser/metrics_web_contents_observer.h"
@@ -150,6 +152,9 @@ int WebLayerMetricsServiceClient::GetPackageNameLimitRatePerMille() {
 
 void WebLayerMetricsServiceClient::RegisterAdditionalMetricsProviders(
     metrics::MetricsService* service) {
+  service->RegisterMetricsProvider(
+      std::make_unique<metrics::ContentStabilityMetricsProvider>(pref_service(),
+                                                                 nullptr));
   service->RegisterMetricsProvider(std::make_unique<PageLoadMetricsProvider>());
 }