Rename single buffer mode to shared buffer mode

Change-Id: Id43d0737d9367981644e498942ebc0077d61038c
diff --git a/libs/gui/GLConsumer.cpp b/libs/gui/GLConsumer.cpp
index 149f5bd..7ef18a8 100644
--- a/libs/gui/GLConsumer.cpp
+++ b/libs/gui/GLConsumer.cpp
@@ -427,7 +427,7 @@
             slot, mSlots[slot].mGraphicBuffer->handle);
 
     // Hang onto the pointer so that it isn't freed in the call to
-    // releaseBufferLocked() if we're in single buffer mode and both buffers are
+    // releaseBufferLocked() if we're in shared buffer mode and both buffers are
     // the same.
     sp<EglImage> nextTextureImage = mEglSlots[slot].mEglImage;