Revert "Get rid of IGraphicBufferAlloc"

This reverts commit 78491c9f694cb0767996503c629776a8eda950d7.

Change-Id: I78d5c0a30ab80265f697f681387872b6763b2d1e
diff --git a/include/gui/ISurfaceComposer.h b/include/gui/ISurfaceComposer.h
index 1112973..9870ba0 100644
--- a/include/gui/ISurfaceComposer.h
+++ b/include/gui/ISurfaceComposer.h
@@ -41,6 +41,7 @@
 struct DisplayStatInfo;
 class HdrCapabilities;
 class IDisplayEventConnection;
+class IGraphicBufferAlloc;
 class IGraphicBufferProducer;
 class ISurfaceComposerClient;
 class Rect;
@@ -88,6 +89,10 @@
     virtual sp<ISurfaceComposerClient> createScopedConnection(
             const sp<IGraphicBufferProducer>& parent) = 0;
 
+    /* create a graphic buffer allocator
+     */
+    virtual sp<IGraphicBufferAlloc> createGraphicBufferAlloc() = 0;
+
     /* return an IDisplayEventConnection */
     virtual sp<IDisplayEventConnection> createDisplayEventConnection() = 0;
 
@@ -200,7 +205,7 @@
         // Java by ActivityManagerService.
         BOOT_FINISHED = IBinder::FIRST_CALL_TRANSACTION,
         CREATE_CONNECTION,
-        UNUSED, // formerly CREATE_GRAPHIC_BUFFER_ALLOC
+        CREATE_GRAPHIC_BUFFER_ALLOC,
         CREATE_DISPLAY_EVENT_CONNECTION,
         CREATE_DISPLAY,
         DESTROY_DISPLAY,