[SystemInfo API] Implement systemInfo.storage.onAvailableCapacityChanged event

chrome/browser/extensions/system_info_event_router.h

Index: chrome/browser/extensions/system_info_event_router.h
diff --git a/chrome/browser/extensions/system_info_event_router.h b/chrome/browser/extensions/system_info_event_router.h
index 2fd8b4f1afd5d7ebbaa4b35a95d4b58e65850c47..b8c330b36c481fde559ffda2b7ba247e33866be3 100644
--- a/chrome/browser/extensions/system_info_event_router.h
+++ b/chrome/browser/extensions/system_info_event_router.h
@@ -10,6 +10,7 @@
 #include "base/file_path.h"
 #include "base/memory/singleton.h"
 #include "base/values.h"
+#include "chrome/browser/extensions/api/system_info_storage/storage_info_observer.h"
 
 namespace extensions {
 
@@ -29,7 +30,7 @@ struct CpuUpdateInfo;
 // Since the system_monitor will be refactored along with media_gallery, once
 // http://crbug.com/145400 is fixed, we need to update SystemInfoEventRouter
 // accordingly.
-class SystemInfoEventRouter {
+class SystemInfoEventRouter : public StorageInfoObserver {
  public:
   static SystemInfoEventRouter* GetInstance();
 
@@ -40,11 +41,14 @@ class SystemInfoEventRouter {
   // Return true if the |event_name| is an event from systemInfo namespace.
   static bool IsSystemInfoEvent(const std::string& event_name);
 
+  // StorageInfoObserver implementation:
+  virtual void OnStorageFreeSpaceChanged(const std::string& id,
+                                         double new_value,
+                                         double old_value);
+
   // TODO(hongbo): The following methods should be likely overriden from
   // SystemMonitor::DevicesChangedObserver once the http://crbug.com/145400
   // is fixed.
-  void OnStorageAvailableCapacityChanged(const std::string& id,
-                                         int64 available_capacity);
   void OnRemovableStorageAttached(const std::string& id,
                                   const string16& name,
                                   const FilePath::StringType& location);