Fix a crash when opening a window.

RenderWidgetHostViewQt::GetViewBounds gets called early than
RenderWidgetHostViewQt::setAdapterClient when a new window is created
by Chromium.

Change-Id: I5ad61fc54ae773200403b222110a1d0ad541f941
Reviewed-by: Arvid Nilsson <anilsson@blackberry.com>
Reviewed-by: Andras Becsi <andras.becsi@digia.com>
Avoid errors when closing the application

This also fixes the crash on shutdown encountered when returning a
TEXTURE_TRANSPORT GLSurfaceHandle from
RenderWidgetHostViewQt::GetCompositingSurface.

Change-Id: Ic92238907a3e7f9d0db4bf114269c1ca5cca5aa6
Reviewed-by: Arvid Nilsson <anilsson@blackberry.com>
Reviewed-by: Andras Becsi <andras.becsi@digia.com>