Add tests for Chrome Stability Metrics.

chrome/browser/metrics/chrome_stability_metrics_provider.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_METRICS_CHROME_STABILITY_METRICS_PROVIDER_H_
 #define CHROME_BROWSER_METRICS_CHROME_STABILITY_METRICS_PROVIDER_H_
 
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 #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;
 }
 
+class PrefService;
+
 // ChromeStabilityMetricsProvider gathers and logs Chrome-specific stability-
 // related metrics.
 class ChromeStabilityMetricsProvider
     : public metrics::MetricsProvider,
       public content::BrowserChildProcessObserver,
       public content::NotificationObserver {
  public:
-  ChromeStabilityMetricsProvider();
+  explicit ChromeStabilityMetricsProvider(PrefService* local_state);
   ~ChromeStabilityMetricsProvider() override;
 
   // metrics::MetricsDataProvider:
   void OnRecordingEnabled() override;
   void OnRecordingDisabled() override;
   void ProvideStabilityMetrics(
       metrics::SystemProfileProto* system_profile_proto) override;
   void ClearSavedStabilityMetrics() override;
 
   // Registers local state prefs used by this class.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(ChromeStabilityMetricsProviderTest,
+                           BrowserChildProcessObserver);
+  FRIEND_TEST_ALL_PREFIXES(ChromeStabilityMetricsProviderTest,
+                           NotificationObserver);
+
   // content::NotificationObserver:
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
   // content::BrowserChildProcessObserver:
   void BrowserChildProcessCrashed(
       const content::ChildProcessData& data,
       int exit_code) 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);
 
   // Records a renderer process crash.
   void LogRendererCrash(content::RenderProcessHost* host,
                         base::TerminationStatus status,
                         int exit_code);
 
+  // Increment an Integer pref value specified by |path|

[Avi (use Gerrit), 2015/09/02 01:11:10]

. at the end of sentences

[Will Harris, 2015/09/02 15:57:53]

Done.

+  void IncrementPrefValue(const char* path);
+
+  // Increment a 64-bit Integer pref value specified by |path|

[Avi (use Gerrit), 2015/09/02 01:11:10]

ditto

[Will Harris, 2015/09/02 15:57:53]

Done.

+  void IncrementLongPrefsValue(const char* path);
+
   // Records a renderer process hang.
   void LogRendererHang();
 
+  PrefService* local_state_;
+
   // Registrar for receiving stability-related notifications.
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeStabilityMetricsProvider);
 };
 
 #endif  // CHROME_BROWSER_METRICS_CHROME_STABILITY_METRICS_PROVIDER_H_