drm_hwcomposer: Add flag for blocking commits

Add a flag to specify whether a commit should be blocking or not.
Default the flag to false, which matches the current behavior.

Change-Id: Ib8f332d8d4d6b8ae1d12f86a980cec8e3efc9da0
Signed-off-by: Drew Davenport <ddavenport@google.com>
diff --git a/drm/DrmAtomicStateManager.cpp b/drm/DrmAtomicStateManager.cpp
index bb26189..9a8769a 100644
--- a/drm/DrmAtomicStateManager.cpp
+++ b/drm/DrmAtomicStateManager.cpp
@@ -101,7 +101,7 @@
     }
   }
 
-  bool nonblock = true;
+  bool nonblock = !args.blocking;
 
   if (args.active) {
     nonblock = false;