Fix assumption about DynamicRefTable in aapt

Packages without any resources should not expect to have
a DynamicRefTable.

Bug:16895517
Bug:17056720
Change-Id: Id006f6bdbf08f30505f6ba5982bc9d1b09db0f0a
diff --git a/tools/aapt/Command.cpp b/tools/aapt/Command.cpp
index 41102fe..c74a373 100644
--- a/tools/aapt/Command.cpp
+++ b/tools/aapt/Command.cpp
@@ -764,12 +764,9 @@
         return 1;
     }
 
+    // The dynamicRefTable can be null if there are no resources for this asset cookie.
+    // This fine.
     const DynamicRefTable* dynamicRefTable = res.getDynamicRefTableForCookie(assetsCookie);
-    if (dynamicRefTable == NULL) {
-        fprintf(stderr, "ERROR: failed to find dynamic reference table for asset cookie %d\n",
-                assetsCookie);
-        return 1;
-    }
 
     Asset* asset = NULL;