CURSORINFO.flags should be checked before capturing its bitmap

webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc

Index: webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
diff --git a/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc b/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
index 204bb00b1602f9d32344e7f0da6145244e1979ca..b9fecbb884f3c6bc25fde4800c7bf8e080a7a048 100644
--- a/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
+++ b/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
@@ -92,13 +92,17 @@ void MouseCursorMonitorWin::Capture() {
     return;
   }
 
-  if (last_cursor_ != cursor_info.hCursor) {
-    last_cursor_ = cursor_info.hCursor;
+  if (cursor_info.flags == CURSOR_SHOWING &&

[Sergey Ulanov, 2016/05/10 20:51:15]

I still think that wont do the right thing. Particularly in Desktop Capture API,
if the cursor hidden we don't want it to be rendered on the screen by
DesktopAndCursorComposer. With this change DesktopAndCursorComposer will not be
notified that the cursor is hidden and it will keep drawing it.
Also in CRD we want to default to arrow in that case instead of using the last
non-hidden cursor.

[Sergey Ulanov, 2016/05/10 20:58:12]

Actually looking at this again I see your point - the Desktop Capture API should
work correctly as OnMouseCursorPosition() will be called with state=OUTSIDE. But
I still think the behavior in CRD (when mode==SHAPE_ONLY) is incorrect.

[Hzj_jie, 2016/05/11 00:55:49]

Done.

[Hzj_jie, 2016/05/11 00:55:49]

Based on our discussion, we will do this,
1. Always return a cursor info to the client. If Windows does not return a valid
cursor, we will return a default one.
2. Add a field in CursorShapeInfo to indicate whether currently the cursor is
shown or not.

+      last_cursor_ != cursor_info.hCursor) {
     // Note that |cursor_info.hCursor| does not need to be freed.
     std::unique_ptr<MouseCursor> cursor(
         CreateMouseCursorFromHCursor(desktop_dc_, cursor_info.hCursor));
-    if (cursor.get())
+    if (cursor) {
+      last_cursor_ = cursor_info.hCursor;
       callback_->OnMouseCursor(cursor.release());
+    } else {
+      last_cursor_ = NULL;
+    }
   }
 
   if (mode_ != SHAPE_AND_POSITION)