Move child process observing from MetricsService to stability provider.

chrome/browser/metrics/metrics_service.h

Index: chrome/browser/metrics/metrics_service.h
===================================================================
--- chrome/browser/metrics/metrics_service.h	(revision 272462)
+++ chrome/browser/metrics/metrics_service.h	(working copy)
@@ -31,8 +31,6 @@
 #include "components/metrics/metrics_provider.h"
 #include "components/metrics/metrics_service_observer.h"
 #include "components/variations/active_field_trials.h"
-#include "content/public/browser/browser_child_process_observer.h"
-#include "content/public/browser/user_metrics.h"
 #include "net/url_request/url_fetcher_delegate.h"
 
 class GoogleUpdateMetricsProviderWin;
@@ -90,7 +88,6 @@
 class MetricsService
     : public base::HistogramFlattener,
       public chrome_browser_metrics::TrackingSynchronizerObserver,
-      public content::BrowserChildProcessObserver,
       public net::URLFetcherDelegate {
  public:
   // The execution phase of the browser.
@@ -170,10 +167,6 @@
       base::HistogramBase::Inconsistency problem) OVERRIDE;
   virtual void InconsistencyDetectedInLoggedCount(int amount) OVERRIDE;
 
-  // Implementation of content::BrowserChildProcessObserver
-  virtual void BrowserChildProcessCrashed(
-      const content::ChildProcessData& data) OVERRIDE;
-
   // This should be called when the application is not idle, i.e. the user seems
   // to be interacting with the application.
   void OnApplicationNotIdle();