Don't reuse LOST_SURFACE for stopped

Fixes: 28218991

If a draw() happens while we are stopped, don't report
that the surface is lost because this will prompt
a tear-down of the surface which isn't desired. It can
result in ViewRootImpl ending up in an internally-bad state
in this case.

Change-Id: If3eb8c6bc8702299e5330bc0917952624dce3b7e
diff --git a/libs/hwui/renderthread/DrawFrameTask.h b/libs/hwui/renderthread/DrawFrameTask.h
index 9bba065..c02d376 100644
--- a/libs/hwui/renderthread/DrawFrameTask.h
+++ b/libs/hwui/renderthread/DrawFrameTask.h
@@ -40,11 +40,14 @@
 class CanvasContext;
 class RenderThread;
 
-enum SyncResult {
-    kSync_OK = 0,
-    kSync_UIRedrawRequired = 1 << 0,
-    kSync_LostSurfaceRewardIfFound = 1 << 1,
+namespace SyncResult {
+enum {
+    OK = 0,
+    UIRedrawRequired = 1 << 0,
+    LostSurfaceRewardIfFound = 1 << 1,
+    ContextIsStopped = 1 << 2,
 };
+}
 
 /*
  * This is a special Super Task. It is re-used multiple times by RenderProxy,