--- a/ipc/chromium/src/base/process_util_win.cc
+++ b/ipc/chromium/src/base/process_util_win.cc
@@ -94,17 +94,21 @@ bool OpenPrivilegedProcessHandle(Process
   if (result == INVALID_HANDLE_VALUE)
     return false;
 
   *handle = result;
   return true;
 }
 
 void CloseProcessHandle(ProcessHandle process) {
-  CloseHandle(process);
+  // closing a handle twice on Windows can be catastrophic - after the first
+  // close the handle value may be reused, so the second close will kill that
+  // other new handle.
+  BOOL ok = CloseHandle(process);
+  DCHECK(ok);
 }
 
 // Helper for GetProcId()
 bool GetProcIdViaGetProcessId(ProcessHandle process, DWORD* id) {
   // Dynamically get a pointer to GetProcessId().
   typedef DWORD (WINAPI *GetProcessIdFunction)(HANDLE);
   static GetProcessIdFunction GetProcessIdPtr = NULL;
   static bool initialize_get_process_id = true;

--- a/ipc/chromium/src/base/process_win.cc
+++ b/ipc/chromium/src/base/process_win.cc
@@ -7,17 +7,17 @@
 #include "base/process_util.h"
 #include "base/scoped_ptr.h"
 
 namespace base {
 
 void Process::Close() {
   if (!process_)
     return;
-  ::CloseHandle(process_);
+  CloseProcessHandle(process_);
   process_ = NULL;
 }
 
 void Process::Terminate(int result_code) {
   if (!process_)
     return;
   ::TerminateProcess(process_, result_code);
 }

--- a/ipc/chromium/src/chrome/common/process_watcher_win.cc
+++ b/ipc/chromium/src/chrome/common/process_watcher_win.cc
@@ -37,17 +37,17 @@ class TimerExpiredTask : public Task, pu
 
   // MessageLoop::Watcher -----------------------------------------------------
 
   virtual void OnObjectSignaled(HANDLE object) {
     // When we're called from KillProcess, the ObjectWatcher may still be
     // watching.  the process handle, so make sure it has stopped.
     watcher_.StopWatching();
 
-    CloseHandle(process_);
+    base::CloseProcessHandle(process_);
     process_ = NULL;
   }
 
  private:
   void KillProcess() {
     if (base::SysInfo::HasEnvVar(env_vars::kHeadless)) {
      // If running the distributed tests, give the renderer a little time
      // to figure out that the channel is shutdown and unwind.
@@ -80,22 +80,22 @@ class TimerExpiredTask : public Task, pu
 // static
 void ProcessWatcher::EnsureProcessTerminated(base::ProcessHandle process
 					     , bool force
 ) {
   DCHECK(process != GetCurrentProcess());
 
   if (!force) {
     WaitForSingleObject(process, INFINITE);
-    CloseHandle(process);
+    base::CloseProcessHandle(process);
     return;
   }
 
   // If already signaled, then we are done!
   if (WaitForSingleObject(process, 0) == WAIT_OBJECT_0) {
-    CloseHandle(process);
+    base::CloseProcessHandle(process);
     return;
   }
 
   MessageLoop::current()->PostDelayedTask(FROM_HERE,
                                           new TimerExpiredTask(process),
                                           kWaitInterval);
 }