Implement systemInfo.storage.onChanged 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..ef12002a47394a09c94b8e6cf9cecb4f969356df 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/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 +41,6 @@ class SystemInfoEventRouter {
   // Return true if the |event_name| is an event from systemInfo namespace.
   static bool IsSystemInfoEvent(const std::string& event_name);
 
-  // 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);
@@ -56,15 +52,21 @@ class SystemInfoEventRouter {
   SystemInfoEventRouter();
   virtual ~SystemInfoEventRouter();
 
-  // Called from any thread to dispatch the systemInfo event to all extension
-  // processes cross multiple profiles.
-  void DispatchEvent(const std::string& event_name,
-      scoped_ptr<base::ListValue> args);
+  // Overriden from StorageInfoObserver:
+  void OnStorageFreeSpaceChanged(const std::string& id,
+                                 double old_value,
+                                 double new_value,
+                                 int threshold);
 
   // The callback for CPU sampling cycle. Called from FILE thread.
   void OnNextCpuSampling(
       scoped_ptr<api::experimental_system_info_cpu::CpuUpdateInfo> info);
 
+  // Called from any thread to dispatch the systemInfo event to all extension
+  // processes cross multiple profiles.
+  void DispatchEvent(const std::string& event_name,
+      scoped_ptr<base::ListValue> args);
+
   // Used to record the event names being watched.
   std::multiset<std::string> watching_event_set_;