Fixes DesktopWindowTreeHostMus::SetSize and IsVisible

ui/views/mus/desktop_window_tree_host_mus.cc

Index: ui/views/mus/desktop_window_tree_host_mus.cc
diff --git a/ui/views/mus/desktop_window_tree_host_mus.cc b/ui/views/mus/desktop_window_tree_host_mus.cc
index 9731c9d9179ff015fb8372768ecfac04c951c7e4..99f19f8269f5484459372a4153e971f1cc802179 100644
--- a/ui/views/mus/desktop_window_tree_host_mus.cc
+++ b/ui/views/mus/desktop_window_tree_host_mus.cc
@@ -122,12 +122,16 @@ void DesktopWindowTreeHostMus::ShowMaximizedWithBounds(
 }
 
 bool DesktopWindowTreeHostMus::IsVisible() const {
+  if (parent_ && !parent_->native_widget_delegate_->AsWidget()->IsVisible())

[msw, 2016/11/09 23:57:55]

Could we simply check !parent->IsVisible() instead? Will the parent's window
visibility match the widget visibility? If not, maybe explain why not?

[sky, 2016/11/10 00:33:47]

Added comment.

+    return false;
   return window()->IsVisible();
 }
 
 void DesktopWindowTreeHostMus::SetSize(const gfx::Size& size) {
+  gfx::Rect screen_bounds = GetWindowBoundsInScreen();

[msw, 2016/11/09 23:57:55]

Hmm, I don't really know why it makes sense to call GetWindowBoundsInScreen here
versus GetBounds (to parallel the SetBounds call below, that also happens to be
the current impl of GetWindowBoundsInScreen with the dips todo), or some other
bounds function, like the old window->bounds(). I can rubber stamp, but maybe
it's worth adding some explanatory comment about the importance of calling one
function over the (seemingly similar) others...

[sky, 2016/11/10 00:33:47]

This should be GetBounds(). Changed.

+  screen_bounds.set_size(size);
   // TODO: handle device scale, http://crbug.com/663524.
-  SetBounds(gfx::Rect(window()->bounds().origin(), size));
+  SetBounds(screen_bounds);
 }
 
 void DesktopWindowTreeHostMus::StackAbove(aura::Window* window) {