Add a new app API to enable watchdog behavior restarts in kiosk apps

extensions/browser/api/runtime/runtime_api.h

Index: extensions/browser/api/runtime/runtime_api.h
diff --git a/extensions/browser/api/runtime/runtime_api.h b/extensions/browser/api/runtime/runtime_api.h
index 187f7b0d7f16d0fb8e9f60cd2d45c50782e698fb..d066925700bfd275ad832036d7ae518089ef79a9 100644
--- a/extensions/browser/api/runtime/runtime_api.h
+++ b/extensions/browser/api/runtime/runtime_api.h
@@ -9,6 +9,8 @@
 
 #include "base/macros.h"
 #include "base/scoped_observer.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/api/runtime/runtime_api_delegate.h"
@@ -28,6 +30,8 @@ namespace content {
 class BrowserContext;
 }
 
+class PrefRegistrySimple;
+
 namespace extensions {
 
 namespace api {
@@ -49,8 +53,23 @@ class RuntimeAPI : public BrowserContextKeyedAPI,
                    public UpdateObserver,
                    public ProcessManagerObserver {
  public:
+  // The status of the restart on watchdog request.
+  enum class RestartOnWatchdogStatus {
+    // The request was made by a different extension other than the first one to
+    // invoke the restartOnWatchdog runtime API.
+    FAILED_NOT_FIRST_EXTENSION,
+
+    // Any previously scheduled restart was successfully canceled.
+    SUCCESS_RESTART_CANCELLED,
+
+    // A restart was successfully scheduled.
+    SUCCESS_RESTART_SCHEDULED,
+  };
+
   static BrowserContextKeyedAPIFactory<RuntimeAPI>* GetFactoryInstance();
 
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
   explicit RuntimeAPI(content::BrowserContext* context);
   ~RuntimeAPI() override;
 
@@ -65,10 +84,16 @@ class RuntimeAPI : public BrowserContextKeyedAPI,
   void OpenURL(const GURL& uninstall_url);
   bool GetPlatformInfo(api::runtime::PlatformInfo* info);
   bool RestartDevice(std::string* error_message);
+
+  RestartOnWatchdogStatus RestartDeviceOnWatchdogTimeout(
+      const std::string& extension_id,
+      int seconds_from_now);
+
   bool OpenOptionsPage(const Extension* extension);
 
  private:
   friend class BrowserContextKeyedAPIFactory<RuntimeAPI>;
+  friend class RestartOnWatchdogApiTest;
 
   // ExtensionRegistryObserver implementation.
   void OnExtensionLoaded(content::BrowserContext* browser_context,
@@ -81,6 +106,17 @@ class RuntimeAPI : public BrowserContextKeyedAPI,
                               const Extension* extension,
                               UninstallReason reason) override;
 
+  // Cancels any previously scheduled restart request.
+  void MaybeCancelRunningWatchdogTimer();
+
+  void ScheduleDelayedRestart(const base::Time& now,
+                              int seconds_from_now,
+                              double stored_last_restart);
+
+  // Called when the restart watchdog timer times out so that it attempts to
+  // execute the restart request scheduled earlier.
+  void OnRestartWatchdogTimeout();
+
   // BrowserContextKeyedAPI implementation:
   static const char* service_name() { return "RuntimeAPI"; }
   static const bool kServiceRedirectedInIncognito = true;
@@ -102,6 +138,12 @@ class RuntimeAPI : public BrowserContextKeyedAPI,
   void RemovePendingOnInstallInfoFromPref(const ExtensionId& extension_id);
   void StorePendingOnInstallInfoToPref(const Extension* extension);
 
+  void SetMinDurationBetweenRestartsForTesting(base::TimeDelta delta) {

[Devlin, 2016/05/25 21:53:22]

const base::TimeDelta&

Also, this can probably be hacker_style() since it's just a setter.

[afakhry, 2016/05/26 00:18:39]

TimeDelta is just an int64_t and is always passed by value:
https://code.google.com/p/chromium/codesearch#search/&q=.*%5C(base::TimeDelta...

Done for the hacker_style() setter.

+    minimum_duration_between_restarts_ = delta;
+  }
+
+  void AllowNonKiostAppsInRestartOnWatchdogForTesting();
+
   std::unique_ptr<RuntimeAPIDelegate> delegate_;
 
   content::BrowserContext* browser_context_;
@@ -118,6 +160,19 @@ class RuntimeAPI : public BrowserContextKeyedAPI,
   ScopedObserver<ProcessManager, ProcessManagerObserver>
       process_manager_observer_;
 
+  // The ID of the first extension to call the restartOnWatchdog API. Any other
+  // extensions to call this API after that will fail.
+  std::string schedule_restart_first_extension_id_;
+
+  // The timer that will trigger a device restart when it times out.
+  base::OneShotTimer watchdog_timer_;
+
+  // The minimum allowed duration between two successive restarts on watchdog
+  // timer.
+  base::TimeDelta minimum_duration_between_restarts_;
+
+  base::WeakPtrFactory<RuntimeAPI> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(RuntimeAPI);
 };
 
@@ -220,6 +275,16 @@ class RuntimeRestartFunction : public UIThreadExtensionFunction {
   ResponseAction Run() override;
 };
 
+class RuntimeRestartOnWatchdogFunction : public UIThreadExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("runtime.restartOnWatchdog",
+                             RUNTIME_RESTARTONWATCHDOG)
+
+ protected:
+  ~RuntimeRestartOnWatchdogFunction() override {}
+  ResponseAction Run() override;
+};
+
 class RuntimeGetPlatformInfoFunction : public UIThreadExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("runtime.getPlatformInfo",