[fsp] Unmount file systems when the providing extension gets unloaded.

chrome/browser/chromeos/file_system_provider/service.h

Index: chrome/browser/chromeos/file_system_provider/service.h
diff --git a/chrome/browser/chromeos/file_system_provider/service.h b/chrome/browser/chromeos/file_system_provider/service.h
index e1949b6977c5e8bade98f1b3c0c10d3ee98198bc..3ed9a73027e26cd0a312b42c591389734ca489b5 100644
--- a/chrome/browser/chromeos/file_system_provider/service.h
+++ b/chrome/browser/chromeos/file_system_provider/service.h
@@ -20,6 +20,12 @@
 #include "chrome/common/extensions/api/file_system_provider.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/browser_context.h"
+#include "extensions/browser/extension_registry_observer.h"
+
+namespace extensions {
+class Extension;
+class ExtensionRegistry;
+}  // namespace extensions
 
 namespace chromeos {
 namespace file_system_provider {
@@ -29,9 +35,11 @@ class ProvidedFileSystemInterface;
 class ServiceFactory;
 
 // Manages and registers the fileSystemProvider service.
-class Service : public KeyedService {
+class Service : public KeyedService,
+                public extensions::ExtensionRegistryObserver {
  public:
-  explicit Service(Profile* profile);
+  explicit Service(Profile* profile,
+                   extensions::ExtensionRegistry* extension_registry);
   virtual ~Service();
 
   // Mounts a file system provided by an extension with the |extension_id|.
@@ -69,6 +77,10 @@ class Service : public KeyedService {
   // BrowserContextKeyedService overrides.
   virtual void Shutdown() OVERRIDE;
 
+  // extensions::ExtensionRegistryObserver overrides.
+  virtual void OnExtensionUnloaded(const extensions::Extension* extension)
+      OVERRIDE;
+
   // Getter for the request manager. Used by the extension API to forward
   // replies. Valid as long as the service.
   RequestManager* request_manager() { return &request_manager_; }
@@ -81,8 +93,12 @@ class Service : public KeyedService {
   void OnRequestUnmountStatus(const ProvidedFileSystemInfo& file_system_info,
                               base::File::Error error);
 
-  RequestManager request_manager_;
   Profile* profile_;
+
+  // Owned by extensions::ExtensionRegistryFactory.
+  extensions::ExtensionRegistry* extension_registry_;
+
+  RequestManager request_manager_;
   ObserverList<Observer> observers_;
   ProvidedFileSystemMap file_system_map_;  // Owns pointers.