more clean-up in preparation of bigger changes

the most important change here is the renaming of
ISurfaceFlingerClient to ISurfaceComposerClient

Change-Id: I94e18b0417f50e06f21377446639c61f65f959b3
diff --git a/libs/surfaceflinger_client/SharedBufferStack.cpp b/libs/surfaceflinger_client/SharedBufferStack.cpp
index 2577dc0..8d03145 100644
--- a/libs/surfaceflinger_client/SharedBufferStack.cpp
+++ b/libs/surfaceflinger_client/SharedBufferStack.cpp
@@ -49,10 +49,6 @@
     return surfaces[i].status;
 }
 
-uint32_t SharedClient::getIdentity(size_t token) const {
-    return uint32_t(surfaces[token].identity);
-}
-
 // ----------------------------------------------------------------------------
 
 
@@ -161,6 +157,12 @@
     return stack.status;
 }
 
+int32_t SharedBufferBase::getIdentity() const
+{
+    SharedBufferStack& stack( *mSharedStack );
+    return stack.identity;
+}
+
 size_t SharedBufferBase::getFrontBuffer() const
 {
     SharedBufferStack& stack( *mSharedStack );