When forking, restore the default exception handler port....

base/process_util_mac.mm

Index: base/process_util_mac.mm
===================================================================
--- base/process_util_mac.mm	(revision 25314)
+++ base/process_util_mac.mm	(working copy)
@@ -7,6 +7,8 @@
 
 #import <Cocoa/Cocoa.h>
 #include <crt_externs.h>
+#include <mach/mach_init.h>
+#include <mach/task.h>
 #include <spawn.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
@@ -21,6 +23,23 @@
 
 namespace base {
 
+void RestoreDefaultExceptionHandler() {
+  // This function is tailored to remove the Breakpad exception handler.
+  // exception_mask matches s_exception_mask in
+  // breakpad/src/client/mac/handler/exception_handler.cc
+  const exception_mask_t exception_mask = EXC_MASK_BAD_ACCESS |
+                                          EXC_MASK_BAD_INSTRUCTION |
+                                          EXC_MASK_ARITHMETIC |
+                                          EXC_MASK_BREAKPOINT;
+
+  // Setting the exception port to MACH_PORT_NULL may not be entirely
+  // kosher to restore the default exception handler, but in practice,
+  // it results in the exception port being set to Apple Crash Reporter,
+  // the desired behavior.
+  task_set_exception_ports(mach_task_self(), exception_mask, MACH_PORT_NULL,
+                           EXCEPTION_DEFAULT, THREAD_STATE_NONE);
+}
+
 NamedProcessIterator::NamedProcessIterator(const std::wstring& executable_name,
                                            const ProcessFilter* filter)
   : executable_name_(executable_name),