Check for CloseHandle failures even when not debugging

chrome/app/close_handle_hook_win.cc

Index: chrome/app/close_handle_hook_win.cc
diff --git a/chrome/app/close_handle_hook_win.cc b/chrome/app/close_handle_hook_win.cc
index 02dfce513d13f9c0ba084cdc6bf0ec77ed2f6fd4..cde247eee44f1acf6ef08124cb97c0f957e04b64 100644
--- a/chrome/app/close_handle_hook_win.cc
+++ b/chrome/app/close_handle_hook_win.cc
@@ -37,7 +37,13 @@ DuplicateHandleType g_duplicate_function = NULL;
 // function.
 BOOL WINAPI CloseHandleHook(HANDLE handle) {
   base::win::OnHandleBeingClosed(handle);
-  return g_close_function(handle);
+  BOOL result = g_close_function(handle);
+  // Check for CloseHandle failures.
+  // urlmon closes a handle that is NULL so we can't fail on that.
+  // Also CloseHandle() under a debugger only throws an exception on handles
+  // that are neither NULL nor INVALID_HANDLE_VALUE.
+  DPCHECK(result || handle == NULL || handle == INVALID_HANDLE_VALUE);

[rvargas (doing something else), 2015/09/15 18:08:04]

This seems like a weird place to looks for close failures.

On one hand, _our_ code should be CHECKing on close failures (yes, all
processes, all build types). That's what base/ generally does and that's what
other parts of the code that call CloseHandle directly should do.

On the other hand, this is an OS hook. While it is intended to help track handle
consistency, it covers all modules loaded on the process so we cannot generally
enforce our policies on them.

If urlmon is closing NULL (or INVALID_HANDLE_VALUE) handles we should fix that.

+  return result;
 }
 
 BOOL WINAPI DuplicateHandleHook(HANDLE source_process,