Update third_party/mach_override to include the fix for building Chromium on 64 bits

third_party/mach_override/README.chromium

Index: third_party/mach_override/README.chromium
===================================================================
--- third_party/mach_override/README.chromium	(revision 150086)
+++ third_party/mach_override/README.chromium	(working copy)
@@ -2,8 +2,8 @@
 Short Name: Part of the mach_star project
 Version: Unknown
 URL: https://github.com/rentzsch/mach_star
-Date: 08/19/2011
-Revision: 87f491f8acef924d2ba90dd55fc23ad64f9d5bbd
+Date: 08/01/2012
+Revision: 6c4965586d28b931d19b428832fe5de968fd7d82
 License: MIT
 Security Critical: Yes
 
@@ -11,18 +11,10 @@
 Description:
 This is the mach_override part of mach_star, namely:
 
-  https://github.com/rentzsch/mach_star/tree/87f491f8acef924d2ba90dd55fc23ad64f9d5bbd
+  https://github.com/rentzsch/mach_star/tree/6c4965586d28b931d19b428832fe5de968fd7d82
 
 This package is used to replace framework functions with different
 implementations at run time.
 
 
-Local Modifications:
-
-reentryIsland is allocated in high memory with vm_allocate rather than the
-heap with malloc by changing the allocation policy to kAllocateHigh. It
-appears probable that putting the reentry island in the heap causes its page
-to lose execute permission at some point under some circumstances, which
-results in a crash on Lion. This modification is temoprary to simply test
-out the theory. If proven, the code will be improved somewhat.
-http://crbug.com/93736.
+Local Modifications: None