Add renderer launch count to stability metrics.

chrome/browser/metrics/chrome_stability_metrics_provider.cc

Index: chrome/browser/metrics/chrome_stability_metrics_provider.cc
diff --git a/chrome/browser/metrics/chrome_stability_metrics_provider.cc b/chrome/browser/metrics/chrome_stability_metrics_provider.cc
index 0742257d1b88aaba350d1e8a21988028e7c157a0..4c417f1d8cf869ca81652b4381104dd7acf05f05 100644
--- a/chrome/browser/metrics/chrome_stability_metrics_provider.cc
+++ b/chrome/browser/metrics/chrome_stability_metrics_provider.cc
@@ -48,6 +48,9 @@ void ChromeStabilityMetricsProvider::OnRecordingEnabled() {
   registrar_.Add(this,
                  content::NOTIFICATION_RENDER_WIDGET_HOST_HANG,
                  content::NotificationService::AllSources());
+  registrar_.Add(this,
+                 content::NOTIFICATION_RENDERER_PROCESS_CREATED,
+                 content::NotificationService::AllSources());
 }
 
 void ChromeStabilityMetricsProvider::OnRecordingDisabled() {
@@ -95,6 +98,20 @@ void ChromeStabilityMetricsProvider::Observe(
       helper_.LogRendererHang();
       break;
 
+    case content::NOTIFICATION_RENDERER_PROCESS_CREATED: {
+      bool was_extension_process = false;
+#if defined(ENABLE_EXTENSIONS)
+      content::RenderProcessHost* host =
+          content::Source<content::RenderProcessHost>(source).ptr();
+      if (extensions::ProcessMap::Get(host->GetBrowserContext())
+              ->Contains(host->GetID())) {
+        was_extension_process = true;
+      }
+#endif
+      helper_.LogRendererLaunched(was_extension_process);
+      break;
+    }
+
     default:
       NOTREACHED();
       break;