Move child process observing from MetricsService to stability provider.

chrome/browser/metrics/chrome_stability_metrics_provider.h

Index: chrome/browser/metrics/chrome_stability_metrics_provider.h
===================================================================
--- chrome/browser/metrics/chrome_stability_metrics_provider.h	(revision 272600)
+++ chrome/browser/metrics/chrome_stability_metrics_provider.h	(working copy)
@@ -9,9 +9,12 @@
 #include "base/metrics/user_metrics.h"
 #include "base/process/kill.h"
 #include "components/metrics/metrics_provider.h"
+#include "content/public/browser/browser_child_process_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
+class PrefRegistrySimple;
+
 namespace content {
 class RenderProcessHost;
 class WebContents;
@@ -19,8 +22,10 @@
 
 // ChromeStabilityMetricsProvider gathers and logs Chrome-specific stability-
 // related metrics.
-class ChromeStabilityMetricsProvider : public metrics::MetricsProvider,
-                                       public content::NotificationObserver {
+class ChromeStabilityMetricsProvider
+    : public metrics::MetricsProvider,
+      public content::BrowserChildProcessObserver,
+      public content::NotificationObserver {
  public:
   ChromeStabilityMetricsProvider();
   virtual ~ChromeStabilityMetricsProvider();
@@ -31,12 +36,19 @@
   virtual void ProvideStabilityMetrics(
       metrics::SystemProfileProto* system_profile_proto) OVERRIDE;
 
+  // Registers local state prefs used by this class.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
  private:
   // content::NotificationObserver:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // content::BrowserChildProcessObserver:
+  virtual void BrowserChildProcessCrashed(
+      const content::ChildProcessData& data) OVERRIDE;
+
   // Logs the initiation of a page load and uses |web_contents| to do
   // additional logging of the type of page loaded.
   void LogLoadStarted(content::WebContents* web_contents);