Hide the cursor on the client when it is hidden on the host

remoting/host/chromeos/mouse_cursor_monitor_aura.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/chromeos/mouse_cursor_monitor_aura.h"
 
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
@@ skipping 35 matching lines @@
       last_mouse_location_ = position;
       callback_->OnMouseCursorPosition(
           INSIDE, webrtc::DesktopVector(position.x(), position.y()));
     }
   }
 }
 
 void MouseCursorMonitorAura::NotifyCursorChanged(const ui::Cursor& cursor) {
   scoped_ptr<SkBitmap> cursor_bitmap(new SkBitmap());
   gfx::Point cursor_hotspot;
+
+  if (cursor.native_type() == ui::kCursorNone) {
+    return;

[Sergey Ulanov, 2015/01/05 18:00:25]

Should we notify the client that the cursor is hidden in this case (i.e. send an
empty cursor message)?

[Wez, 2015/01/05 20:02:46]

Yes, please do. There is even an EmptyCursorShape() helper function in the
EmptyCursorFilter header. :)

[kelvinp, 2015/01/06 02:22:18]

Whoa, excellent point.
I have taken the step a little further to make sure that the client
always hide the cursor when the host send an empty cursor.
Please take another look. 

+  }
+
   if (!ui::GetCursorBitmap(cursor, cursor_bitmap.get(), &cursor_hotspot)) {
     LOG(ERROR) << "Failed to load bitmap for cursor type:"
                << cursor.native_type();
     return;
   }
 
   last_cursor_ = cursor;
 
   // There is a bug (crbug.com/436993) in aura::GetCursorBitmap() such that it
   // it would return a scale-factor-100 bitmap with a scale-factor-200 hotspot.
@@ skipping 13 matching lines @@
   scoped_ptr<webrtc::DesktopFrame> image(
       SkiaBitmapDesktopFrame::Create(cursor_bitmap.Pass()));
   scoped_ptr<webrtc::MouseCursor> cursor_shape(new webrtc::MouseCursor(
       image.release(),
       webrtc::DesktopVector(cursor_hotspot.x(), cursor_hotspot.y())));
 
   callback_->OnMouseCursor(cursor_shape.release());
 }
 
 }  // namespace remoting