Fix up bookmarks bar folders to always be scrolled to the top when they are opened.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.h"
 
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_utils.h"
@@ skipping 769 matching lines @@
   [self layOutWindowWithHeight:height];
 }
 
 - (void)layOutWindowWithHeight:(CGFloat)height {
   // Lay out the window by adjusting all button widths to be consistent, then
   // base the window width on this ideal button width.
   CGFloat buttonWidth = [self adjustButtonWidths];
   CGFloat windowWidth = buttonWidth + padding_;
   NSPoint newWindowTopLeft = [self windowTopLeftForWidth:windowWidth
                                                   height:height];
+
   // Make sure as much of a submenu is exposed (which otherwise would be a
   // problem if the parent button is close to the bottom of the screen).
   if ([parentController_ isKindOfClass:[self class]]) {
     CGFloat minimumY = NSMinY([[[self window] screen] visibleFrame]) +
                        bookmarks::kScrollWindowVerticalMargin +
                        height;
     newWindowTopLeft.y = MAX(newWindowTopLeft.y, minimumY);
   }
+
   NSWindow* window = [self window];
   NSRect windowFrame = NSMakeRect(newWindowTopLeft.x,
                                   newWindowTopLeft.y - height,
                                   windowWidth, height);
   [window setFrame:windowFrame display:NO];
+
   NSRect folderFrame = NSMakeRect(0, 0, windowWidth, height);
   [folderView_ setFrame:folderFrame];
+
+  // For some reason, when opening a "large" bookmark folder (containing 12 or
+  // more items) using the keyboard, the scroll view seems to want to be
+  // offset by default: [ http://crbug.com/101099 ].  Explicitly reseting the
+  // scroll position here is a bit hacky, but it does seem to work.
+  [[scrollView_ contentView] scrollToPoint:NSMakePoint(0, 0)];
+
   NSSize newSize = NSMakeSize(windowWidth, 0.0);
   [self adjustWindowLeft:newWindowTopLeft.x size:newSize scrollingBy:0.0];
   [self configureWindowLevel];
+
   [window display];
 }
 
 // TODO(mrossetti): See if the following can be moved into view's viewWillDraw:.
 - (CGFloat)adjustButtonWidths {
   CGFloat width = bookmarks::kBookmarkMenuButtonMinimumWidth;
   // Use the cell's size as the base for determining the desired width of the
   // button rather than the button's current width. -[cell cellSize] always
   // returns the 'optimum' size of the cell based on the cell's contents even
   // if it's less than the current button size. Relying on the button size
@@ skipping 1168 matching lines @@
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController