Don't dirty MIP chain when damage bounds is empty

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 8fffc4d917d85f58a4808da429ac925a3f39e62b..1b25402b4f480ccee81e1deb14894d81110e1567 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -2317,13 +2317,13 @@ void GrGLGpu::flushRenderTarget(GrGLRenderTarget* target, const SkIRect* bound)
             }
         }
     }
+
+    // Mark any MIP chain and resolve buffer as dirty if and only if there is a non-empty bounds.
     if (nullptr == bound || !bound->isEmpty()) {
         target->flagAsNeedingResolve(bound);
-    }
-
-    GrTexture *texture = target->asTexture();
-    if (texture) {
-        texture->texturePriv().dirtyMipMaps(true);
+        if (GrTexture *texture = target->asTexture()) {
+            texture->texturePriv().dirtyMipMaps(true);
+        }
     }
 }