Update media galleries scan results, even when zero.

chrome/browser/media_galleries/media_scan_manager_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/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 366 matching lines @@
   size_t galleries_before = gallery_prefs()->known_galleries().size();
 
   MediaGalleryPrefId ungranted_scan =
       AddGallery("uscan", MediaGalleryPrefInfo::kScanResult, 1, 0, 0);
   MediaGalleryPrefId granted_scan =
       AddGallery("gscan", MediaGalleryPrefInfo::kScanResult, 0, 2, 0);
   gallery_prefs()->SetGalleryPermissionForExtension(*extension(), granted_scan,
                                                     true);
   EXPECT_EQ(galleries_before + 2, gallery_prefs()->known_galleries().size());
 
-  // Run once with no scan results. "uscan" should go away, but "gscan" should
-  // be unaffected.
+  // Run once with no scan results. "uscan" should go away and "gscan" should
+  // have its scan counts updated.
   MediaFolderFinder::MediaFolderFinderResults found_folders;
   SetFindFoldersResults(true, found_folders);
 
   MediaGalleryScanResult file_counts;
   SetExpectedScanResults(0 /*gallery_count*/, file_counts);
   StartScan();
 
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(1, FindFolderDestroyCount());
   EXPECT_EQ(galleries_before + 1, gallery_prefs()->known_galleries().size());
-  CheckFileCounts(granted_scan, 0, 2, 0);
+  CheckFileCounts(granted_scan, 0, 0, 0);
 
   MediaGalleryPrefId id =
       AddGallery("uscan", MediaGalleryPrefInfo::kScanResult, 1, 1, 1);
   EXPECT_NE(id, ungranted_scan);
   ungranted_scan = id;
 
   // Add scan results near the existing scan results.
   file_counts.audio_count = 0;
   file_counts.image_count = 0;
   file_counts.video_count = 7;
@@ skipping 32 matching lines @@
   CheckFileCounts(auto_id, 1, 0, 0);
   CheckFileCounts(user_id, 0, 2, 0);
   CheckFileCounts(scan_id, 0, 0, 3);
 
   MediaFolderFinder::MediaFolderFinderResults found_folders;
   MediaGalleryScanResult file_counts;
   file_counts.audio_count = 4;
   base::FilePath path = MakeTestFolder("auto/dir1");
   found_folders[path] = file_counts;
 
+  file_counts.audio_count = 6;
+  path = MakeTestFolder("scan");
+  found_folders[path] = file_counts;
+
   file_counts.audio_count = 5;
   path = MakeTestFolder("user/dir2");
   found_folders[path] = file_counts;
 
-  file_counts.audio_count = 6;
-  path = MakeTestFolder("scan");
-  found_folders[path] = file_counts;
-
   SetFindFoldersResults(true, found_folders);
 
   file_counts.audio_count = 0;
   SetExpectedScanResults(0 /*gallery_count*/, file_counts);
   StartScan();
 
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(1, FindFolderDestroyCount());
   EXPECT_EQ(galleries_before + 3, gallery_prefs()->known_galleries().size());
   CheckFileCounts(auto_id, 4, 0, 0);
   CheckFileCounts(user_id, 5, 0, 0);
   CheckFileCounts(scan_id, 6, 0, 0);
+
+  EXPECT_EQ(1U, found_folders.erase(path));
+  SetFindFoldersResults(true, found_folders);
+  SetExpectedScanResults(0 /*gallery_count*/, file_counts);
+  StartScan();
+
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(2, FindFolderDestroyCount());
+  EXPECT_EQ(galleries_before + 3, gallery_prefs()->known_galleries().size());
+  CheckFileCounts(auto_id, 4, 0, 0);
+  CheckFileCounts(user_id, 0, 0, 0);
+  CheckFileCounts(scan_id, 6, 0, 0);
 }