allow canvas to force conservative clips (for speed)

tests/PictureTest.cpp

Index: tests/PictureTest.cpp
diff --git a/tests/PictureTest.cpp b/tests/PictureTest.cpp
index 05aec092c3254fa83a8d102a01fd4ebcdb7c99b2..3bc91d78a71afa76df536a2e6e339bb3dc4bc64d 100644
--- a/tests/PictureTest.cpp
+++ b/tests/PictureTest.cpp
@@ -1570,8 +1570,8 @@ static void test_clip_bound_opt(skiatest::Reporter* reporter) {
     path2.addOval(rect3);
     SkIRect clipBounds;
     SkPictureRecorder recorder;
-    // Minimalist test set for 100% code coverage of
-    // SkPictureRecord::updateClipConservativelyUsingBounds
+
+    // Testing conservative-raster-clip that is enabled by PictureRecord
     {
         SkCanvas* canvas = recorder.beginRecording(10, 10);
         canvas->clipPath(invPath, SkRegion::kIntersect_Op);