[Mac] Only enable the CFBundleBlocker in the browser process.

chrome/app/chrome_main_delegate.cc

 // 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 "chrome/app/chrome_main_delegate.h"
 
 #include <stddef.h>
 #include <string>
 
 #include "base/base_paths.h"
@@ skipping 472 matching lines @@
   }
 #endif
 
 #if defined(OS_MACOSX)
   // Give the browser process a longer treadmill, since crashes
   // there have more impact.
   const bool is_browser = !command_line.HasSwitch(switches::kProcessType);
   ObjcEvilDoers::ZombieEnable(true, is_browser ? 10000 : 1000);
 
   SetUpBundleOverrides();
-  chrome::common::mac::EnableCFBundleBlocker();
+
+  // Only enable the CFBundleBlocker in the browser. In child processes,
+  // the sandbox will block access to loadable bundle locations.
+  if (is_browser)
+    chrome::common::mac::EnableCFBundleBlocker();
 #endif
 
   Profiling::ProcessStarted();
 
   base::trace_event::TraceLog::GetInstance()->SetArgumentFilterPredicate(
       base::Bind(&IsTraceEventArgsWhitelisted));
 
 #if defined(OS_WIN)
   v8_breakpad_support::SetUp();
 #endif
@@ skipping 534 matching lines @@
     case version_info::Channel::CANARY:
       return true;
     case version_info::Channel::DEV:
     case version_info::Channel::BETA:
     case version_info::Channel::STABLE:
     default:
       // Don't enable instrumentation.
       return false;
   }
 }