get rid of ISurface

ISurface was only used to get the IGraphicBufferProducer from
a Layer. It's now replaced by a BBinder subclass / IBinder and
is only used as a handle to the surface, to both refer to it
and manage its life-time.

Also cleaned-up a bit the ISurfaceComposer interface and
"create layer" code path.

Change-Id: I68d0e02d57b862cffb31d5168c3bc10cea0906eb
diff --git a/services/surfaceflinger/LayerDim.h b/services/surfaceflinger/LayerDim.h
index e1ea9bd..e19bf52 100644
--- a/services/surfaceflinger/LayerDim.h
+++ b/services/surfaceflinger/LayerDim.h
@@ -32,7 +32,8 @@
 class LayerDim : public Layer
 {
 public:    
-                LayerDim(SurfaceFlinger* flinger, const sp<Client>& client);
+                LayerDim(SurfaceFlinger* flinger, const sp<Client>& client,
+                        const String8& name, uint32_t w, uint32_t h, uint32_t flags);
         virtual ~LayerDim();
 
     virtual void onDraw(const sp<const DisplayDevice>& hw, const Region& clip) const;
@@ -44,7 +45,6 @@
 
     virtual bool isFixedSize() const      { return true; }
     virtual bool isVisible() const;
-    virtual sp<ISurface> createSurface();
 };
 
 // ---------------------------------------------------------------------------