Index: chrome/browser/cocoa/browser_frame_view.mm
===================================================================
--- chrome/browser/cocoa/browser_frame_view.mm	(revision 43477)
+++ chrome/browser/cocoa/browser_frame_view.mm	(working copy)
@@ -243,7 +243,7 @@
 
     [[NSGraphicsContext currentContext] setPatternPhase:phase];
     [themeImageColor set];
-    NSRectFill(dirtyRect);
+    NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);
     themed = YES;
   } else if (gradient) {
     NSPoint startPoint = NSMakePoint(NSMinX(bounds), NSMaxY(bounds));