Mac: Make it easier for views to correctly draw with a theme.

ui/base/cocoa/nsview_additions.h

 // 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.
 
 #ifndef UI_BASE_COCOA_NSVIEW_ADDITIONS_H_
 #define UI_BASE_COCOA_NSVIEW_ADDITIONS_H_
 
 #import <Cocoa/Cocoa.h>
 
 @interface NSView (ChromeAdditions)
@@ skipping 11 matching lines @@
 - (BOOL)cr_isAboveView:(NSView*)otherView;
 
 // Ensures that the z-order of |subview| is correct relative to |otherView|.
 - (void)cr_ensureSubview:(NSView*)subview
             isPositioned:(NSWindowOrderingMode)place
               relativeTo:(NSView *)otherView;
 
 // Return best color for keyboard focus ring.
 - (NSColor*)cr_keyboardFocusIndicatorColor;
 
+// Invoke |block| on this view and all descendants.
+- (void)cr_recursivelyInvokeBlock:(void (^)(id view))block;
+
 // Set needsDisplay for this view and all descendants.
 - (void)cr_recursivelySetNeedsDisplay:(BOOL)flag;
 
 // Draw using ancestorView's drawRect function into this view's rect. Do any
 // required translating or flipping to transform between the two coordinate
 // systems.
 - (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)rect;
 
 // Used by ancestorView in the above draw call, to look up the child view that
 // it is actually drawing to.
 - (NSView*)cr_viewBeingDrawnTo;
 
 @end
 
 #endif  // UI_BASE_COCOA_NSVIEW_ADDITIONS_H_