diff --git a/src/gpu/GrSurfaceDrawContext.cpp b/src/gpu/GrSurfaceDrawContext.cpp
index a9c1d81..dff2642 100644
--- a/src/gpu/GrSurfaceDrawContext.cpp
+++ b/src/gpu/GrSurfaceDrawContext.cpp
@@ -443,7 +443,7 @@
         }
     }
 
-    for (GrSubRun& subRun : blob->subRunList()) {
+    for (const GrSubRun& subRun : blob->subRunList()) {
         subRun.draw(clip, viewMatrix, glyphRunList, this);
     }
 }
diff --git a/src/gpu/text/GrTextBlob.h b/src/gpu/text/GrTextBlob.h
index eff3e80..57a60d6 100644
--- a/src/gpu/text/GrTextBlob.h
+++ b/src/gpu/text/GrTextBlob.h
@@ -338,6 +338,8 @@
     bool isEmpty() const { return fHead == nullptr; }
     Iterator begin() { return Iterator{ fHead.get()}; }
     Iterator end() { return Iterator{nullptr}; }
+    Iterator begin() const { return Iterator{ fHead.get()}; }
+    Iterator end() const { return Iterator{nullptr}; }
     GrSubRun& front() const {return *fHead; }
 
     std::unique_ptr<GrSubRun, GrSubRunAllocator::Destroyer> fHead{nullptr};
@@ -413,7 +415,7 @@
     const Key& key() const;
     size_t size() const;
 
-    GrSubRunList& subRunList() {
+    const GrSubRunList& subRunList() const {
         return fSubRunList;
     }