Rename ISurfaceTexture and SurfaceTexture

The C++ class names don't match what the classes do, so rename
ISurfaceTexture to IGraphicBufferProducer, and SurfaceTexture to
GLConsumer.

Bug 7736700

Change-Id: Ia03e468888025b5cae3c0ee1995434515dbea387
diff --git a/services/surfaceflinger/LayerBase.cpp b/services/surfaceflinger/LayerBase.cpp
index 9b03c74..31ef941 100644
--- a/services/surfaceflinger/LayerBase.cpp
+++ b/services/surfaceflinger/LayerBase.cpp
@@ -506,7 +506,7 @@
 sp<ISurface> LayerBaseClient::createSurface()
 {
     class BSurface : public BnSurface, public LayerCleaner {
-        virtual sp<ISurfaceTexture> getSurfaceTexture() const { return 0; }
+        virtual sp<IGraphicBufferProducer> getSurfaceTexture() const { return 0; }
     public:
         BSurface(const sp<SurfaceFlinger>& flinger,
                 const sp<LayerBaseClient>& layer)