Add HANDLE_FLAG_PROTECT_FROM_CLOSE flag to Tracked/ScopedHandle.

base/win/scoped_handle.cc

Index: base/win/scoped_handle.cc
diff --git a/base/win/scoped_handle.cc b/base/win/scoped_handle.cc
index 33a8aa5c743b7b27eab6349fa1f0ee953dca6909..bc1858d4756b1e9c203896bc0a40b8de9afe20d7 100644
--- a/base/win/scoped_handle.cc
+++ b/base/win/scoped_handle.cc
@@ -132,10 +132,6 @@ void ActiveVerifier::InstallVerifier() {
   // This lock only protects against races in this module, which is fine.
   AutoNativeLock lock(g_lock.Get());
   g_active_verifier = verifier ? verifier : new ActiveVerifier(true);
-
-  // TODO(shrikant): Enable handle verifier after figuring out
-  // AppContainer/DuplicateHandle error.
-  g_active_verifier->Disable();
 #endif
 }
 
@@ -156,6 +152,10 @@ void ActiveVerifier::StartTracking(HANDLE handle, const void* owner,
   if (!enabled_)
     return;
 
+  // Idea here is to make our handles non-closable until we close it ourselves.
+  ::SetHandleInformation(handle, HANDLE_FLAG_PROTECT_FROM_CLOSE,
+                         HANDLE_FLAG_PROTECT_FROM_CLOSE);
+
   // Grab the thread id before the lock.
   DWORD thread_id = GetCurrentThreadId();
 
@@ -176,6 +176,15 @@ void ActiveVerifier::StopTracking(HANDLE handle, const void* owner,
   if (!enabled_)
     return;
 
+  // We expect handle to be protected till this point.
+  DWORD flags = 0;
+  ::GetHandleInformation(handle, &flags);
+  if (!(flags & HANDLE_FLAG_PROTECT_FROM_CLOSE))

[grt (UTC plus 2), 2015/05/01 13:26:14]

minor style nit: check what you care about rather than testing and then
CHECK(FALSE). for example:
CHECK_NE(0U, (flags & HANDLE_FLAG_PROTECT_FROM_CLOSE));

[Shrikant Kelkar, 2015/05/01 17:48:41]

Done.

+    CHECK(FALSE);
+
+  // Unprotect handle so that it could be closed.
+  ::SetHandleInformation(handle, HANDLE_FLAG_PROTECT_FROM_CLOSE, 0);
+
   AutoNativeLock lock(*lock_);
   HandleMap::iterator i = map_.find(handle);
   if (i == map_.end())
@@ -203,6 +212,15 @@ void ActiveVerifier::OnHandleBeingClosed(HANDLE handle) {
   if (i == map_.end())
     return;
 
+  // Mask out all protected handle close attempts. This will give us
+  // idea if protecting handle has any effect or not.
+  // TODO(shrikant): Remove this code once we see results of the above
+  // mentioned experiment.
+  DWORD flags = 0;
+  ::GetHandleInformation(handle, &flags);
+  if (flags & HANDLE_FLAG_PROTECT_FROM_CLOSE)
+    return;
+
   Info other = i->second;
   base::debug::Alias(&other);
   CHECK(false);