Port unload_uitest.cc and enable some of the tests on linux....

base/process_util_posix.cc

Index: base/process_util_posix.cc
===================================================================
--- base/process_util_posix.cc	(revision 14443)
+++ base/process_util_posix.cc	(working copy)
@@ -22,6 +22,7 @@
 #include "base/scoped_ptr.h"
 #include "base/sys_info.h"
 #include "base/time.h"
+#include "base/waitable_event.h"
 
 const int kMicrosecondsPerSecond = 1000000;
 
@@ -207,7 +208,7 @@
   // has been installed.  This means that when a SIGCHLD is sent, it will exit
   // depending on behavior external to this function.
   //
-  // This function is used primarilly for unit tests, if we want to use it in
+  // This function is used primarily for unit tests, if we want to use it in
   // the application itself it would probably be best to examine other routes.
   int status = -1;
   pid_t ret_pid = waitpid(handle, &status, WNOHANG);
@@ -243,7 +244,11 @@
 
 bool WaitForSingleProcess(ProcessHandle handle, int wait_milliseconds) {
   bool waitpid_success;
-  int status = WaitpidWithTimeout(handle, wait_milliseconds, &waitpid_success);
+  int status;
+  if (wait_milliseconds == base::kNoTimeout)
+    waitpid_success = (waitpid(handle, &status, 0) != -1);
+  else
+    status = WaitpidWithTimeout(handle, wait_milliseconds, &waitpid_success);
   if (status != -1) {
     DCHECK(waitpid_success);
     return WIFEXITED(status);