Repaint windows on screen unlock.

ui/views/win/hwnd_message_handler.cc

Index: ui/views/win/hwnd_message_handler.cc
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index 190af84fb10f45f60582c4b25c731669369a96e2..6edf5baa6d5c2203608c40725253380dc9a19910 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -6,6 +6,8 @@
 
 #include <dwmapi.h>
 #include <shellapi.h>
+#include <wtsapi32.h>
+#pragma comment(lib, "wtsapi32.lib")
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
@@ -1385,6 +1387,8 @@ LRESULT HWNDMessageHandler::OnCreate(CREATESTRUCT* create_struct) {
     scroll_styles_set_ = true;
   }
 #endif
+  WTSRegisterSessionNotification(hwnd(), NOTIFY_FOR_THIS_SESSION);

[sky, 2014/01/16 16:36:37]

Docs indicate you need to unregister.

+
   // TODO(beng): move more of NWW::OnCreate here.
   return 0;
 }
@@ -2321,6 +2325,35 @@ void HWNDMessageHandler::OnWindowPosChanged(WINDOWPOS* window_pos) {
   SetMsgHandled(FALSE);
 }
 
+void HWNDMessageHandler::ForceRedrawWindow(int attempts) {
+  HDESK input_desktop = ::OpenInputDesktop(0, 0, GENERIC_READ);
+  if (!input_desktop) {

[cpu_(ooo_6.6-7.5), 2014/01/16 18:35:08]

son, I am not sure what you are trying to do here but I think you meant to
detect the interactive desktop

Use GetThreadDesktop and GetUserObjectInformation(UOI_IO).

Also this function as is is more expensive than its name implies, how about

bool IsInteactiveDesktop();

void HWNDMessageHandler::OnSessionChange(WPARAM status_code, ..) {
  static int count = 0;
  if (status_code == WTS_SESSION_UNLOCK)
    if (!IsInteractiveDesktop())
       PostTask(... OnSessionChange)


}

+    // Presents will continue to fail as long as the input desktop is
+    // unavailable.
+    if (--attempts <= 0)
+      return;
+    base::MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&HWNDMessageHandler::ForceRedrawWindow,
+                   weak_factory_.GetWeakPtr(),
+                   attempts),
+        base::TimeDelta::FromMilliseconds(500));
+    return;
+  }
+  ::CloseDesktop(input_desktop);
+  InvalidateRect(hwnd(), NULL, FALSE);
+}
+
+void HWNDMessageHandler::OnSessionChange(WPARAM status_code,
+                                         PWTSSESSION_NOTIFICATION session_id) {
+  // Direct3D presents are ignored while the screen is locked, so force the
+  // window to be redrawn on unlock.
+  if (status_code == WTS_SESSION_UNLOCK)
+    ForceRedrawWindow(10);
+
+  SetMsgHandled(FALSE);
+}
+
 void HWNDMessageHandler::HandleTouchEvents(const TouchEvents& touch_events) {
   base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
   for (size_t i = 0; i < touch_events.size() && ref; ++i)