Adding (empty) placeholder button to 'Other bookmarks' folder is unnecessary.

When user removes the last item (folder/page) from 'Other bookmarks' folder,
the folder itself is hidden; hence adding (empty) button is unnecessary. So
just close the folder before hiding it.

TEST=
1) Launch chrome and bookmark a page or folder into 'Other Bookmarks'.
2) Right-click on the bookmarked page/folder in the 'Other Bookmarks' from Bookmark bar.
3) Choose to 'Cut'/'Delete' and observe.
4) (empty) placeholder button should not remain after 'Other bookmarks' folder is hidden.

BUG=257538
R=asvitkine@chromium.org

Review URL: https://codereview.chromium.org/485003002

Cr-Commit-Position: refs/heads/master@{#291160}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@291160 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.mm

@@ -762,7 +762,7 @@ NSRect GetFirstButtonFrameForHeight(CGFloat height) {
 - (void)adjustWindowForButtonCount:(NSUInteger)buttonCount {
   NSRect folderFrame = [folderView_ frame];
   CGFloat newMenuHeight =
-      (CGFloat)[self menuHeightForButtonCount:[buttons_ count]];
+      (CGFloat)[self menuHeightForButtonCount:buttonCount];
   CGFloat deltaMenuHeight = newMenuHeight - NSHeight(folderFrame);
   // If the height has changed then also change the origin, and adjust the
   // scroll (if scrolling).
@@ -1936,9 +1936,10 @@ static BOOL ValueInRangeInclusive(CGFloat low, CGFloat value, CGFloat high) {
         [folderController_
             offsetFolderMenuWindow:NSMakeSize(0.0, chrome::kBookmarkBarHeight)];
     }
-  } else {
+  } else if (parentButton_ != [barController_ otherBookmarksButton]) {
     // If all nodes have been removed from this folder then add in the
-    // 'empty' placeholder button.
+    // 'empty' placeholder button except for "Other bookmarks" folder
+    // as we are going to hide it.
     NSRect buttonFrame =
         GetFirstButtonFrameForHeight([self menuHeightForButtonCount:1]);
     BookmarkButton* button = [self makeButtonForNode:nil
@@ -1948,7 +1949,12 @@ static BOOL ValueInRangeInclusive(CGFloat low, CGFloat value, CGFloat high) {
     buttonCount = 1;
   }
 
-  [self adjustWindowForButtonCount:buttonCount];
+  // buttonCount will be 0 if "Other bookmarks" folder is empty, so close
+  // the folder before hiding it.
+  if (buttonCount == 0)
+    [barController_ closeBookmarkFolder:nil];
+  else if (buttonCount > 0)
+    [self adjustWindowForButtonCount:buttonCount];
 
   if (animate && !ignoreAnimations_)
     NSShowAnimationEffect(NSAnimationEffectDisappearingItemDefault, poofPoint,

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller_unittest.mm

@@ -1166,6 +1166,43 @@ TEST_F(BookmarkBarFolderControllerMenuTest, MoveRemoveAddButtons) {
   [folder validateMenuSpacing];
 }
 
+TEST_F(BookmarkBarFolderControllerMenuTest, RemoveLastButtonOtherBookmarks) {
+  BookmarkModel* model = BookmarkModelFactory::GetForProfile(profile());
+  const BookmarkNode* otherBookmarks = model->other_node();
+
+  BookmarkButton* otherButton = [bar_ otherBookmarksButton];
+  ASSERT_TRUE(otherButton);
+
+  // Open the folder to get the folderController_.
+  [[otherButton target] openBookmarkFolderFromButton:otherButton];
+  BookmarkBarFolderController* folder = [bar_ folderController];
+  EXPECT_TRUE(folder);
+
+  // Initially there is only (empty) placeholder button, hence buttonCount
+  // should be 1.
+  NSArray* buttons = [folder buttons];
+  EXPECT_TRUE(buttons);
+  EXPECT_EQ(1U, [buttons count]);
+
+  // Add a new bookmark into 'Other bookmarks' folder.
+  model->AddURL(otherBookmarks, otherBookmarks->child_count(),
+                ASCIIToUTF16("TheOther"),
+                GURL("http://www.other.com"));
+
+  // buttonCount still should be 1, as we remove the (empty) placeholder button
+  // when adding a new button to an empty folder.
+  EXPECT_EQ(1U, [buttons count]);
+
+  // Now we have only 1 button; remove it so that 'Other bookmarks' folder
+  // is hidden.
+  [folder removeButton:0 animate:NO];
+  EXPECT_EQ(0U, [buttons count]);
+
+  // 'Other bookmarks' folder gets closed once we remove the last button. Hence
+  // folderController_ should be NULL.
+  EXPECT_FALSE([bar_ folderController]);
+}
+
 TEST_F(BookmarkBarFolderControllerMenuTest, ControllerForNode) {
   BookmarkModel* model = BookmarkModelFactory::GetForProfile(profile());
   const BookmarkNode* root = model->bookmark_bar_node();