Fix darkly-drawn Show All button in Downloads Shelf.

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 19 matching lines @@
 - (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.
+// systems, and optionally clip to the ancestor view's bounds.
+- (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)dirtyRect
+     clippedToAncestorBounds:(BOOL)clipToAncestorBounds;
+
+// Same as cr_drawUsingAncestor:inRect:clippedToAncestorBounds: except always
+// clips to the ancestor view's bounds.
 - (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)dirtyRect;
 
 // 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_