Fix darkly-drawn Show All button in Downloads Shelf.

ui/base/cocoa/nsview_additions.h

Index: ui/base/cocoa/nsview_additions.h
diff --git a/ui/base/cocoa/nsview_additions.h b/ui/base/cocoa/nsview_additions.h
index 467c04fa62066c81f3a9860e14c9015d38d14941..62043b2ab06e35d95613194d796875b7e6a8f354 100644
--- a/ui/base/cocoa/nsview_additions.h
+++ b/ui/base/cocoa/nsview_additions.h
@@ -37,7 +37,12 @@
 
 // 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