Fix reduceOpsTaskSplitting + image_from_yuv_textures

SkTHashMap->remove does not like if you try to remove
an entry that isn't in there. In that case, we don't
want to do anything.

Bug: skia:10877
Change-Id: Ib87aac7a132c78915ec18724f847c44c2c3efa80
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/360596
Auto-Submit: Adlai Holler <adlai@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Adlai Holler <adlai@google.com>
diff --git a/src/gpu/GrRenderTaskCluster.cpp b/src/gpu/GrRenderTaskCluster.cpp
index 676ec49..83f585f 100644
--- a/src/gpu/GrRenderTaskCluster.cpp
+++ b/src/gpu/GrRenderTaskCluster.cpp
@@ -72,7 +72,9 @@
         // Tasks with 0 or multiple targets are treated as full barriers
         // for all their targets.
         for (int j = 0; j < task->numTargets(); j++) {
-            lastTaskMap->remove(task->target(0));
+            if (lastTaskMap->find(task->target(0))) {
+                lastTaskMap->remove(task->target(0));
+            }
         }
         return false;
     }