ozone: Add OzoneSurface object that is owned by compositor, GLSurface

ui/aura/window_tree_host_ozone.cc

Index: ui/aura/window_tree_host_ozone.cc
diff --git a/ui/aura/window_tree_host_ozone.cc b/ui/aura/window_tree_host_ozone.cc
index cb3ddb9a3012264e72a1006c2e856c1277c81730..b5dc6662b077bbf5715ed5c783b4a069cbabee00 100644
--- a/ui/aura/window_tree_host_ozone.cc
+++ b/ui/aura/window_tree_host_ozone.cc
@@ -26,8 +26,6 @@ WindowTreeHostOzone::WindowTreeHostOzone(const gfx::Rect& bounds)
       gfx::SurfaceFactoryOzone::GetInstance();
   widget_ = surface_factory->GetAcceleratedWidget();
 
-  surface_factory->AttemptToResizeAcceleratedWidget(widget_, bounds_);

[rjkroege, 2014/03/24 16:07:04]

I see that this change is necessary to compile but will the SurfaceOzone end up
being resized correctly without a different replacement?

[spang, 2014/03/24 16:42:11]

This is redundant. The surface gets its size from the compositor size, and the
compositor is initialized from the window bounds inside
WindowTreeHost::InitCompositor().

WindowTreeHostOzone should not concern itself with the surface, only the window.

[rjkroege, 2014/03/24 20:23:15]

in implementations where it matters, how does the widget get its size?

[spang, 2014/03/24 21:58:28]

Sizing upon initialization goes this way:

  1. Window is created with an initial bounds. This sets the initial size in the
windowing system (future: WindowFactoryOzone::CreateWindow). 
  2. WindowTreeHost calls GetBounds(), which gets the current bounds from the
windowing system, and uses that value to initialize the compositor
(Compositor::SetScaleAndSize).
  3. The compositor plumbs the size down into SoftwareOutputDeviceOzone.
  4. SoftwareOutputDeviceOzone calls AttemptToResizeAcceleratedWidget

That's what I meant when I said this was redundant. The same call already
happens via another path.

Let's let the compositor drive the surface sizing and not worry about it from
WindowTreeHost.

-
   base::MessagePumpOzone::Current()->AddDispatcherForRootWindow(this);
   CreateCompositor(GetAcceleratedWidget());
 }