3 files changed, 31 insertions, 15 deletions

diff --git a/chrome/browser/extensions/extensions_service.cc b/chrome/browser/extensions/extensions_service.cc
index 66b4371..df59e04 100644
--- a/chrome/browser/extensions/extensions_service.cc
+++ b/chrome/browser/extensions/extensions_service.cc
@@ -273,7 +273,7 @@ void ExtensionsService::InstallExtension(const FilePath& extension_path) {
 void ExtensionsService::UpdateExtension(const std::string& id,
                                         const FilePath& extension_path,
                                         bool alert_on_error,
-                                        Callback* callback) {
+                                        ExtensionInstallCallback* callback) {
   if (callback) {
     if (install_callbacks_.find(extension_path) != install_callbacks_.end()) {
       // We can't have multiple outstanding install requests for the same
@@ -284,7 +284,8 @@ void ExtensionsService::UpdateExtension(const std::string& id,
       delete callback;
       return;
     }
-    install_callbacks_[extension_path] = linked_ptr<Callback>(callback);
+    install_callbacks_[extension_path] =
+        linked_ptr<ExtensionInstallCallback>(callback);
   }
 
   if (!GetExtensionById(id)) {
diff --git a/chrome/browser/extensions/extensions_service.h b/chrome/browser/extensions/extensions_service.h
index 81a44d7..4b28169 100644
--- a/chrome/browser/extensions/extensions_service.h
+++ b/chrome/browser/extensions/extensions_service.h
@@ -37,10 +37,27 @@ class UserScriptMaster;
 
 typedef std::vector<Extension*> ExtensionList;
 
+// A callback for when installs finish. If the Extension* parameter is
+// null then the install failed.
+typedef Callback2<const FilePath&, Extension*>::Type ExtensionInstallCallback;
+
+// This is an interface class to encapsulate the dependencies that
+// ExtensionUpdater has on ExtensionsService. This allows easy mocking.
+class ExtensionUpdateService {
+ public:
+  virtual ~ExtensionUpdateService() {}
+  virtual const ExtensionList* extensions() const = 0;
+  virtual void UpdateExtension(const std::string& id,
+                               const FilePath& path,
+                               bool alert_on_error,
+                               ExtensionInstallCallback* callback) = 0;
+  virtual Extension* GetExtensionById(const std::string& id) = 0;
+};
 
 // Manages installed and running Chromium extensions.
 class ExtensionsService
-    : public base::RefCountedThreadSafe<ExtensionsService> {
+    : public ExtensionUpdateService,
+      public base::RefCountedThreadSafe<ExtensionsService> {
  public:
 
   // TODO(port): Move Crx package definitions to ExtentionCreator. They are
@@ -84,10 +101,10 @@ class ExtensionsService
                     const FilePath& install_directory,
                     MessageLoop* frontend_loop,
                     MessageLoop* backend_loop);
-  ~ExtensionsService();
+  virtual ~ExtensionsService();
 
   // Gets the list of currently installed extensions.
-  const ExtensionList* extensions() const {
+  virtual const ExtensionList* extensions() const {
     return &extensions_;
   }
 
@@ -100,18 +117,16 @@ class ExtensionsService
   // immediately loaded.
   void InstallExtension(const FilePath& extension_path);
 
-  // A callback for when installs finish. If the Extension* parameter is
-  // null then the install failed.
-  typedef Callback2<const FilePath&, Extension*>::Type Callback;
-
   // Updates a currently-installed extension with the contents from
   // |extension_path|. The |alert_on_error| parameter controls whether the
   // user will be notified in the event of failure. If |callback| is non-null,
   // it will be called back when the update is finished (in success or failure).
   // This is useful to know when the service is done using |extension_path|.
   // Also, this takes ownership of |callback| if it's non-null.
-  void UpdateExtension(const std::string& id, const FilePath& extension_path,
-                       bool alert_on_error, Callback* callback);
+  virtual void UpdateExtension(const std::string& id,
+                               const FilePath& extension_path,
+                               bool alert_on_error,
+                               ExtensionInstallCallback* callback);
 
   // Uninstalls the specified extension. Callers should only call this method
   // with extensions that exist.
@@ -140,7 +155,7 @@ class ExtensionsService
   void GarbageCollectExtensions();
 
   // Lookup an extension by |id|.
-  Extension* GetExtensionById(const std::string& id);
+  virtual Extension* GetExtensionById(const std::string& id);
 
   // Lookup an extension by |url|.  This uses the host of the URL as the id.
   Extension* GetExtensionByURL(const GURL& url);
@@ -220,7 +235,7 @@ class ExtensionsService
   scoped_refptr<ExtensionsServiceBackend> backend_;
 
   // Stores data we'll need to do callbacks as installs complete.
-  typedef std::map<FilePath, linked_ptr<Callback> > CallbackMap;
+  typedef std::map<FilePath, linked_ptr<ExtensionInstallCallback> > CallbackMap;
   CallbackMap install_callbacks_;
 
   // Is the service ready to go?
diff --git a/chrome/browser/extensions/extensions_service_unittest.cc b/chrome/browser/extensions/extensions_service_unittest.cc
index 92cd377..b195151 100644
--- a/chrome/browser/extensions/extensions_service_unittest.cc
+++ b/chrome/browser/extensions/extensions_service_unittest.cc
@@ -315,7 +315,7 @@ class ExtensionsServiceTest
   }
 
  protected:
-  // A class to record whether a ExtensionsService::Callback has fired, and
+  // A class to record whether a ExtensionInstallCallback has fired, and
   // to remember the args it was called with.
   class CallbackRecorder {
    public:
@@ -375,7 +375,7 @@ class ExtensionsServiceTest
     ASSERT_TRUE(file_util::PathExists(path));
 
     CallbackRecorder callback_recorder;
-    ExtensionsService::Callback* callback = NULL;
+    ExtensionInstallCallback* callback = NULL;
     if (use_callback) {
       callback = NewCallback(&callback_recorder,
                              &CallbackRecorder::CallbackFunc);