Compute bounds union while combining path range draw path batches

src/gpu/batches/GrDrawPathBatch.cpp

Index: src/gpu/batches/GrDrawPathBatch.cpp
diff --git a/src/gpu/batches/GrDrawPathBatch.cpp b/src/gpu/batches/GrDrawPathBatch.cpp
index 4a68820763e56df2419e56f0289cf9dc0015b5a5..1395d083286c7482a9c85bd5c0ef63adc81a0aca 100644
--- a/src/gpu/batches/GrDrawPathBatch.cpp
+++ b/src/gpu/batches/GrDrawPathBatch.cpp
@@ -102,6 +102,7 @@ bool GrDrawPathRangeBatch::onCombineIfPossible(GrBatch* t, const GrCaps& caps) {
         draw->fY = head->fY;
         that->fDraws.popHead();
     }
+    this->joinBounds(that->fBounds);
     return true;
 }