Add --use-more-webui runtime flag to toggle WebUI replacements for native dialogs.

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

Index: chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm
diff --git a/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm b/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm
index 2bd43da1330dbc5240bccd96242203b15d8e8367..3569a619425dd2ea41a34a923a1aa3a9d7f0e605 100644
--- a/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm
+++ b/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.mm
@@ -588,22 +588,16 @@ void RecordAppLaunch(Profile* profile, GURL url) {
     return;
   }
 
-#if defined(WEBUI_DIALOGS)
-  browser_->OpenBookmarkManagerEditNode(node->id());
-#else
-  // There is no real need to jump to a platform-common routine at
-  // this point (which just jumps back to objc) other than consistency
-  // across platforms.
+  // This jumps to a platform-common routine at this point (which may just
+  // jump back to objc or may use the WebUI dialog).
   //
   // TODO(jrg): identify when we NO_TREE.  I can see it in the code
   // for the other platforms but can't find a way to trigger it in the
   // UI.
   BookmarkEditor::Show([[self view] window],
                        browser_->profile(),
-                       node->parent(),
-                       BookmarkEditor::EditDetails(node),
+                       BookmarkEditor::EditDetails::EditNode(node),
                        BookmarkEditor::SHOW_TREE);
-#endif
 }
 
 - (IBAction)cutBookmark:(id)sender {
@@ -681,15 +675,10 @@ void RecordAppLaunch(Profile* profile, GURL url) {
   const BookmarkNode* parent = [self nodeFromMenuItem:sender];
   if (!parent)
     parent = bookmarkModel_->bookmark_bar_node();
-#if defined(WEBUI_DIALOGS)
-  browser_->OpenBookmarkManagerAddNodeIn(parent->id());
-#else
   BookmarkEditor::Show([[self view] window],
                        browser_->profile(),
-                       parent,
-                       BookmarkEditor::EditDetails(),
+                       BookmarkEditor::EditDetails::AddNodeInFolder(parent),
                        BookmarkEditor::SHOW_TREE);
-#endif
 }
 
 // Might be called from the context menu over the bar OR over a