CURSORINFO::ptScreenPos is in full desktop coordinate

So in MouseCursorMonitorWin, we do not need to translate it again.

Bug: webrtc:7950
Change-Id: I39145e8031f7eea2c2f07c0ba666e1f327d8609b
Reviewed-on: https://chromium-review.googlesource.com/651667
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Commit-Queue: Zijie He <zijiehe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#19698}

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 43174cb..174036e 100644
--- a/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
+++ b/webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc
@@ -138,6 +138,7 @@
   if (mode_ != SHAPE_AND_POSITION)
     return;
 
+  // CURSORINFO::ptScreenPos is in full desktop coordinate.
   DesktopVector position(cursor_info.ptScreenPos.x, cursor_info.ptScreenPos.y);
   bool inside = cursor_info.flags == CURSOR_SHOWING;
 
@@ -165,8 +166,7 @@
 
   // TODO(zijiehe): Remove this overload.
   callback_->OnMouseCursorPosition(inside ? INSIDE : OUTSIDE, position);
-  callback_->OnMouseCursorPosition(
-      position.subtract(GetFullscreenRect().top_left()));
+  callback_->OnMouseCursorPosition(position);
 }
 
 DesktopRect MouseCursorMonitorWin::GetScreenRect() {