Add end to end test for Media galleries scan API.

chrome/browser/media_galleries/media_galleries_scan_result_dialog_controller_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/run_loop.h"
@@ skipping 28 matching lines @@
   explicit MockMediaGalleriesScanResultDialog(
       const DialogDestroyedCallback& callback)
       : update_count_(0),
         dialog_destroyed_callback_(callback) {
   }
 
   virtual ~MockMediaGalleriesScanResultDialog() {
     dialog_destroyed_callback_.Run(update_count_);
   }
 
-  // MockMediaGalleriesScanResultDialog implementation.
+  // MediaGalleriesScanResultDialog implementation.
   virtual void UpdateResults() OVERRIDE {
     update_count_++;
   }
 
   // Number up times UpdateResults has been called.
   int update_count() {
     return update_count_;
   }
 
  private:
+  // MediaGalleriesScanResultDialog implementation.
+  virtual void AcceptDialogForTesting() OVERRIDE {
+  }
+
   int update_count_;
 
   DialogDestroyedCallback dialog_destroyed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(MockMediaGalleriesScanResultDialog);
 };
 
 }  // namespace
 
 class MediaGalleriesScanResultDialogControllerTest : public testing::Test {
@@ skipping 378 matching lines @@
   MediaGalleriesScanResultDialogController::OrderedScanResults results =
       controller()->GetGalleryList();
   ASSERT_EQ(5U, results.size());
   EXPECT_EQ(first, results[0].pref_info.pref_id);
   EXPECT_EQ(second, results[1].pref_info.pref_id);
   EXPECT_EQ(third, results[2].pref_info.pref_id);
   EXPECT_EQ(fourth, results[3].pref_info.pref_id);
   EXPECT_EQ(fifth, results[4].pref_info.pref_id);
   controller()->DialogFinished(false);
 }