AAPT2: Add library support

Change-Id: I307f56d9631784ab29ee4156d94886f9b2f25b30
diff --git a/tools/aapt2/Png.h b/tools/aapt2/Png.h
index bc80754..4577ab8 100644
--- a/tools/aapt2/Png.h
+++ b/tools/aapt2/Png.h
@@ -17,6 +17,7 @@
 #ifndef AAPT_PNG_H
 #define AAPT_PNG_H
 
+#include "BigBuffer.h"
 #include "Source.h"
 
 #include <iostream>
@@ -29,7 +30,7 @@
         int grayScaleTolerance = 0;
     };
 
-    bool process(const Source& source, std::istream& input, std::ostream& output,
+    bool process(const Source& source, std::istream& input, BigBuffer* outBuffer,
                  const Options& options, std::string* outError);
 };