Fix darkly-drawn Show All button in Downloads Shelf.

ui/base/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.
 
 #include "base/mac/sdk_forward_declarations.h"
 #import "ui/base/cocoa/nsview_additions.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 
 #include "base/logging.h"
 
@@ skipping 57 matching lines @@
 
 - (void)cr_recursivelySetNeedsDisplay:(BOOL)flag {
   [self setNeedsDisplay:YES];
   for (NSView* child in [self subviews])
     [child cr_recursivelySetNeedsDisplay:flag];
 }
 
 static NSView* g_ancestorBeingDrawnFrom = nil;
 static NSView* g_childBeingDrawnTo = nil;
 
-- (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)dirtyRect {
+- (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)dirtyRect
+     clippedToAncestorBounds:(BOOL)clipToAncestorBounds {
   gfx::ScopedNSGraphicsContextSaveGState scopedGSState;
   NSRect frame = [self convertRect:[self bounds] toView:ancestorView];
   NSAffineTransform* transform = [NSAffineTransform transform];
   if ([self isFlipped] == [ancestorView isFlipped]) {
     [transform translateXBy:-NSMinX(frame) yBy:-NSMinY(frame)];
   } else {
     [transform translateXBy:-NSMinX(frame) yBy:NSMaxY(frame)];
     [transform scaleXBy:1.0 yBy:-1.0];
   }
   [transform concat];
 
   // This can be made robust to recursive calls, but is as of yet unneeded.
   DCHECK(!g_ancestorBeingDrawnFrom && !g_childBeingDrawnTo);
   g_ancestorBeingDrawnFrom = ancestorView;
   g_childBeingDrawnTo = self;
-  [ancestorView drawRect:NSIntersectionRect(
-                             [ancestorView bounds],
-                             [self convertRect:dirtyRect toView:ancestorView])];
+  NSRect drawRect = [self convertRect:dirtyRect toView:ancestorView];
+  if (clipToAncestorBounds) {
+    drawRect = NSIntersectionRect([ancestorView bounds], drawRect);
+  }
+  [ancestorView drawRect:drawRect];
   g_childBeingDrawnTo = nil;
   g_ancestorBeingDrawnFrom = nil;
 }
 
+- (void)cr_drawUsingAncestor:(NSView*)ancestorView inRect:(NSRect)dirtyRect {
+  [self cr_drawUsingAncestor:ancestorView
+                      inRect:dirtyRect
+     clippedToAncestorBounds:YES];
+}
+
 - (NSView*)cr_viewBeingDrawnTo {
   if (!g_ancestorBeingDrawnFrom)
     return self;
   DCHECK(g_ancestorBeingDrawnFrom == self);
   return g_childBeingDrawnTo;
 }
 
 @end