Do not allow multiline input when naming bookmarks/folders on Mac

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

 // Copyright (c) 2011 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 <stack>
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_editor_base_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/profiles/profile.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_all_tabs_controller.h"
+#import "chrome/browser/ui/cocoa/bookmarks/bookmark_cell_single_line.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_editor_controller.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_tree_browser_cell.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
 @interface BookmarkEditorBaseController ()
 
 // Return the folder tree object for the given path.
@@ skipping 531 matching lines @@
     [self didChangeValueForKey:@"folderTreeArray"];
 
     // Expose the parent folder children.
     [folderTreeView_ expandItem:parentInfo];
 
     // Select the new folder node and put the folder name into edit mode.
     selection = [selection indexPathByAddingIndex:[children count] - 1];
     [self setTableSelectionPath:selection];
     NSInteger row = [folderTreeView_ selectedRow];
     DCHECK(row >= 0);
+
+    // Put the cell into single-line mode before putting it into edit mode.
+    NSCell* folderCell = [folderTreeView_ preparedCellAtColumn:0 row:row];
+    if ([folderCell
+          respondsToSelector:@selector(setUsesSingleLineMode:)]) {
+      [folderCell setUsesSingleLineMode:YES];
+    }
+
     [folderTreeView_ editColumn:0 row:row withEvent:nil select:YES];
   }
 }
 
 - (void)createNewFolders {
   AutoReset<BOOL> creatingNewFoldersSetter(&creatingNewFolders_, YES);
   // Scan the tree looking for nodes marked 'newFolder' and create those nodes.
   NSArray* folderTreeArray = [self folderTreeArray];
   for (BookmarkFolderInfo *folderInfo in folderTreeArray) {
     [self createNewFoldersForFolder:folderInfo
@@ skipping 72 matching lines @@
 }
 
 // Implementing isEqual: allows the NSTreeController to preserve the selection
 // and open/shut state of outline items when the data changes.
 - (BOOL)isEqual:(id)other {
   return [other isKindOfClass:[BookmarkFolderInfo class]] &&
       folderNode_ == [(BookmarkFolderInfo*)other folderNode];
 }
 
 @end