Alternate NTP: Don't hide bookmark bar on instant

chrome/browser/ui/cocoa/nsview_additions.mm

 // Copyright (c) 2012 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/nsview_additions.h"
 
+#include "base/logging.h"
+
 #if !defined(MAC_OS_X_VERSION_10_7) || \
     MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
 
 @interface NSView (LionAPI)
 - (NSSize)convertSizeFromBacking:(NSSize)size;
 @end
 
 #endif  // 10.7
 
+namespace {
+
+// Returns YES if |firstView| is above |secondView|.
+BOOL IsViewAboveView(NSView* firstView, NSView* secondView) {
+  NSArray* subviews = [[firstView superview] subviews];
+
+  NSUInteger firstIndex = [subviews indexOfObject:firstView];
+  DCHECK_NE(NSNotFound, firstIndex);
+
+  NSUInteger secondIndex = [subviews indexOfObject:secondView];
+  DCHECK_NE(NSNotFound, secondIndex);
+
+  return firstIndex > secondIndex;
+}
+
+}  // namespace
+
 @implementation NSView (ChromeAdditions)
 
 - (CGFloat)cr_lineWidth {
   // All shipping retina macs run at least 10.7.
   if (![self respondsToSelector:@selector(convertSizeFromBacking:)])
     return 1;
   return [self convertSizeFromBacking:NSMakeSize(1, 1)].width;
 }
 
 - (BOOL)cr_isMouseInView {
   NSPoint mouseLoc = [[self window] mouseLocationOutsideOfEventStream];
   mouseLoc = [[self superview] convertPoint:mouseLoc fromView:nil];
   return [self hitTest:mouseLoc] == self;
 }
 
+- (void)cr_ensureSubview:(NSView*)subview
+            isPositioned:(NSWindowOrderingMode)place
+              relativeTo:(NSView *)otherView {
+  DCHECK(place == NSWindowAbove || place == NSWindowBelow);
+  BOOL isAbove = place == NSWindowAbove;
+  if ([[subview superview] isEqual:self] &&
+      IsViewAboveView(subview, otherView) == isAbove) {
+    return;
+  }
+
+  [subview removeFromSuperview];
+  [self addSubview:subview
+        positioned:place
+        relativeTo:otherView];
+}
+
 @end