Implement IO_OUTPUT + SurfaceTexture

Change-Id: Id96fecd6d768196523330c5eda77c4ee86b9bd3c
diff --git a/rsFBOCache.cpp b/rsFBOCache.cpp
index d50f3e0..1da327f 100644
--- a/rsFBOCache.cpp
+++ b/rsFBOCache.cpp
@@ -50,7 +50,7 @@
         return;
     }
     if (a != NULL) {
-        if (!a->getIsTexture()) {
+        if (!(a->getIsTexture() || (a->mHal.state.usageFlags & RS_ALLOCATION_USAGE_IO_OUTPUT))) {
             ALOGE("Invalid Color Target");
             return;
         }