aura: Don't allow empty delegated frames.

Drop them in the IPC layer. And DCHECK in RenderWidgetHostViewAura
that frames have at last one render pass. Renderer will always
produce frames with a render pass.

R=piman
BUG=263069

Review URL: https://codereview.chromium.org/25624002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226671 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226671