From 33abef4875a0b3fc77496246f00258ea2b31fcb0 Mon Sep 17 00:00:00 2001
From: liyuqian <liyuqian@google.com>
Date: Wed, 31 Oct 2018 10:51:13 -0700
Subject: [PATCH] Check needs_painting in RasterCache::Prepare
 (flutter/engine#6708)

Otherwise, this may trigger `FML_DCHECK(needs_painting())`. We haven't
caused crashes for our users because it probably requires a locally
debug engine build to trigger the assert.
---
 engine/src/flutter/flow/raster_cache.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/engine/src/flutter/flow/raster_cache.cc b/engine/src/flutter/flow/raster_cache.cc
index 017b907e161..d20c65df5b1 100644
--- a/engine/src/flutter/flow/raster_cache.cc
+++ b/engine/src/flutter/flow/raster_cache.cc
@@ -164,7 +164,9 @@ void RasterCache::Prepare(PrerollContext* context,
                                   context->texture_registry,
                                   context->raster_cache,
                                   context->checkerboard_offscreen_layers};
-                              layer->Paint(paintContext);
+                              if (layer->needs_painting()) {
+                                layer->Paint(paintContext);
+                              }
                             });
   }
 }